I suppose this depends upon how far back you choose to go but people have been making artistic visual representations of themselves for a long time. In my period (roughly 1350-1800 but specifically, 1500-1750) we have surviving portraits of people that give us an approximation of how they looked and dressed. When it comes to makeup, we have recipes for face creams and powders, rouges, greases, lotions, and perfumes that have survived.

So, in the sixteenth century, we know that women used a 'foundation' that was a mixture of white lead, white vinegar, and egg whites and in the eighteenth century, we know that both men and women used rouge derived from cochineals (crushed red beetles). Mentions of these concoctions and the recipes themselves appeared in sources as diverse as William Horman's Vulgaria and the private diaries of members of the court; urine was another common cosmetic aid as it was believed that bathing in it would help lighten the complexion. We know from Samuel Pepys's diary that his wife used puppy urine for this purpose and we know from John Bulwer that men and women would use Spanish paper and red leather as a means of adding color back into the face.

Aside from portraits and recipes, we also have written descriptions of people that have survived. Thus, we have the description of Queen Mary I (Bloody Mary) from the Venetian ambassador to her court:

'She is of low rather than of middling stature, but, although short, she has not personal defect in her limbs, nor is any part of her body deformed. She is of spare and delicate frame, quite unlike her father, who was tall and stout; nor does she resemble her mother, who, if not tall, was nevertheless bulky. Her face is well formed, as shown by her features and lineaments, and as seen by her portraits. When younger she was considered, not merely tolerably handsome, but of beauty exceeding mediocrity. At present, with the exception of some wrinkles, caused more by anxieties than by age, which makes her appear some years older, her aspect, for the rest, is very grave. Her eyes are so piercing that they inspire not only respect, but fear in those on whom she fixes them, although she is very shortsighted, being unable to read or do anything else unless she has her sight quite close to what she wishes to peruse or to see distinctly. Her voice is rough and loud, almost like a man’s, so that when she peaks she is always heard a long way off. In short, she is a seemly woman, and never to be loathed for ugliness, even at her present age, without considering her degree of queen. But whatever may be the amount deducted from her physical endowments, as much more may with truth, and without flattery, be added to those of her mind, as, besides the facility and quickness of her understanding, which comprehends whatever is intelligible to others, even to those who are not of her own sex (a marvellous gift for a woman), she is skilled in five languages, not merely understanding, but speaking four of them fluently – English, Latin, French, Spanish, and Italian, in which last, however, she does not venture to converse, although it is well known to her; but the replies she gives in Latin, and her very intelligent remarks made in that tongue surprise everybody….'

Hanson, Marilee. "A Contemporary Description of Queen Mary I, 1557 – Primary Sources" http://englishhistory.net/tudor/queen-mary-i-description/

From these disparate pieces of evidence, we're able to construct a fairly accurate representation of people's physical appearance and cosmetic routines though we do still have to speculate about a lot of the practicalities. But that just leaves plenty of room for future research to be done!