I applied to PhD programs twice, the first to study the history of the United States and the second to study art history. In between I completed an interdisciplinary MA, specifically NYU's John W. Draper program. It is my understanding that this program specifically recruits from unsuccessful applicants to NYU's PhD programs (I think the University of Chicago has a similar program - other universities might as well). While I am happy I did this program because I ended up getting into my first-choice PhD program after the two years, I am not happy I did it because it was enormously expensive and I am now carrying a large amount of student loan debt because of it. Right now I'm a newly-minted PhD with no academic job who is doing some freelancing and otherwise being supported by my SO while I'm on the job market again. So, this perspective will inform what I have to say next:

1. As far as increasing your chance to get accepted, the biggest thing that no one at my undergraduate institution told me (or that I was unwilling or unable to hear), is that your statement of purpose needs to be specific. While it's a relatively short document, you need to show an understanding of the outlines of the field you propose to study, as well as propose an actual historical question you want to solve or investigate. You can't just say (even if you say it in really sophisticated language) "gee golly, I sure do love the Civil War and would love to study that." If you're having trouble identifying a concrete historical question you are interested in, then you need to think long and hard about why you are applying to graduate school, or at least to PhD programs. If you are currently in undergrad and your school offers departmental honors or the option to write a thesis do that. A history of successful independent research will go a long way towards making you an attractive candidate.

2. What about Plan B (or Plan A for people who think they want a PhD but aren't sure what to study)? First of all, if you come from a well-to-do family or otherwise have $70k-100k to spend on an MA, I really do think that the Draper Program and similar are fantastic. It's just not a good idea to go into debt before embarking on the low pay and uncertain outcomes of a humanities PhD, but if you can afford it, great! I know some people who got MA's from NYU for free or cheap, but that involved either having parents who worked there (tuition remission) or working there themselves (also tuition remission, and also can only attend part time while also working a 40 hour a week job). If you can't afford a private school and can't/don't want to get a job at one, and you didn't get into a program, another option is an MA from a state university, especially if you can do it while working and/or living with your parents, to minimize debt. The history department at your local state flagship university will likely have a terminal MA program that you can attend for in-state tuition, and often part-time. Obviously, this might still depend on your financial and job situation. I'm from a small state where something like 3/4 of the total state population lives within an hour of the flagship university, so maybe if you're from Nebraska this won't work as well.

3. Another Plan B is to get a job in a related field, like at a museum or historical society. This will get you hands-on experience with historical materials and research, and probably allow you to make the acquaintance of historians and other professionals in the field. A bonus of this approach is that you might find you like working and have no interest in going to grad school, in which case you have saved yourself a lot of time and financial hardship.

4. Once you get in: I found there was a fairly serious leap in difficulty from undergrad (at an excellent but perhaps not top-tier state university) to NYU. I had more reading that was more difficult, and I was also working 20 hours a week and commuting from central Brooklyn to Manhattan. I drank a lot of coffee and lost a lot of sleep. I found a similarly serious leap from NYU to my PhD program, where the reading was even more vigorous and the classes were much smaller, giving me less room to hide if I hadn't done the reading. I also added TAing and graduate service activities, but subtracted paid work. My PhD university was on the quarter system, so I also had to cram more learning into a smaller amount of time. But I also found that the PhD program, as much work as it was, was incredibly freeing. All you have to do in such a program is work on your chosen field of study. You literally aren't allowed to do anything else. This is a great great feeling if you love the work, and I think it's why a lot of us stick with academia even though the rewards can be so few and far in between.

I found that coursework, especially when I was also TAing, was the hardest I have ever worked. Note that your TA load will vary widely depending on the school you go to. I went to an exclusive private university for my PhD, so my TA load was pretty light (they hardly needed TAs at all - many classes were assigned one just because the grad student needed a TA job as part of his or her training), and I wasn't required to do it at all as a first-year. If you go to some larger, more cash-strapped schools, you might TA from the first semester onward as often as every single semester. This can and should figure into your calculus about which grad program to attend, as should funding, job placement outcomes, and the like. After coursework is oral exams. My programs oral exams were relatively light and informal, but I understand that for many they can be brutal. Hopefully some of the historians here who did old-school history orals can share how that is. After orals is dissertation proposal writing and then dissertation writing. Writing a dissertation is hard work, but I also found that I wasn't terribly busy in terms of total hours worked while writing mine. I'm an efficient worker, and I found that my brain was just not capable of writing for eight hours a day. Research, maybe, but when I was actually writing I would aim to get two hours of good solid writing done in a day. The rest of the time I would spend researching, searching for a job, or taking care of domestic tasks and generally being a supportive partner.

OK, I hope this helps. I am happy to answer questions that anyone has.

What are good strategies to get accepted?

Anecdotally (but with a bit more than hearsay,) the program I was in depended mostly on faculty recommendation letters than much else. As most of academia is reputationally-based, letters from well-known folks within the field the applicant was planning on pursuing were quite valuable. Slightly less valuable was a letter from a well-known scholar for a student planning on studying something outside the recommender's field. Certainly grades and test scores matter, but more as a foot-in-the-door than anything else. In my program, real funding decisions were mostly based on recommendations. This of course presupposes that the applicant is proposing a field of study supported by the program to which they're applying. That is, if you apply to study some field of history that the department to which you're applying doesn't support/have faculty that teach/care about/whatever, you've wasted your time.

How much work do you have to expect?

The first year is tough. I went BA-->PhD with the MA granted as a formality after my second year. I still remember my first day of grad school, being completely lost as my cohort, most of which held an MA, discussed a book. I'd read the book, but had zero clue where it fit in the literature and sat there for three hours, bewildered. I did a lot of outside reading. The most valuable catch-up books I read were Iggers' Historiography in the Twentieth Century and Eric Foner (ed) The New American History. (Now called American History Now, and edited by Lisa McGirr and Foner) Those books saved my bacon.

Advice for starting out: read the above (if Amercanist, otherwise ask your future advisor for a book similar to Foner/McGirr above that applies to your area) and during your first couple of semesters, read every damned word. As you get better at understanding what books are doing and how they fit in to the greater picture, some skimming and intro/conclusion reading becomes OK. In your third year, skimming is pretty much the norm.

Ideally, you shape your course work as a research launch pad. If you can tailor your courses and seminar work to your later dissertation interest, you'll be able to complete your dissie much more quickly, and will (IMO) increase your chances of completing the degree.

Speak with instructors as you take your courses, asking if you can tailor writings a little to include whatever you're planning on covering in your dissertation. See if it's permissible to use writing seminar courses to work on your diss. proposal/prospectus. Try not to take much course work outside of your major field. Some will likely be required/unavoidable, but keep it to a minimum.

In terms of managing stress, I treated grad school like a full-time job. I was lucky in that my spouse was working and I had TA money coming in, so there weren't big financial concerns. This will of course vary. I had my little office where I spent non-class or library time. I was there every day like a job.

My program was quite rigorous, but also very informal. Professors and students (even most undergrads) used first names. We had frequent get-togethers at local watering holes. Having a couple of beers and arguing historiography with well-known professors is a lot of fun.

And lastly, think long and hard about the realities of grad school in the humanities. Jobs are few and far between. At best. I adjuncted for three years before finally landing a tenure-track job. Landing that job required moving my family away from everything we knew. For us, it's worked out pretty well. For others I know, not so much. Adjuncts make less than poverty wages, and Asst. Profs generally not a whole lot more. I didn't get into this for the money, but there are very serious realities to consider. Do you want to be 35 and making $30K a year? Can you live on that? Do you want a roommate for the rest of your life? What of a family? Will you have a spouse/partner that works? Children to feed? I'd bet that most everyone who has completed a PhD knows at least one person from their cohort that left academia over these issues. Likely more than one. Think it through completely before you commit yourself to a decade(-ish) of study and work for very little reward.

I don't mean to be Debbie Downer -- grad school was awesome, really -- but don't go in with illusions, either.