I was wondering how much fashion changed from the 18th into the 19th century. ... Did the advent of technology change much of this? Did female fashion change a lot too?

Men's and women's fashions both changed quite a bit throughout the 18th and 19th centuries, in both subtle and obvious ways; we can look at and discuss the changes occurring between 1795 and 1805, but they don't represent a shift from early modern to industrial in terms of the techniques and materials used. For the most part, the changes in fashion resulted from the shift from the ornate Rococo decorative arts movement to more simplified Neoclassical forms over the course of the 1770s and 1780s: men and women stopped powdering their hair and wore it in more simple styles, soberer colors and white became de rigueur, men's waistcoats became shorter and more fitted, women's gowns lost internal supports and their waistlines rose. Following the turn of the century, brighter colors returned for men and women (though for men, this was mainly in the waistcoat), men wore tight pantaloons and then looser trousers, women's shoes lost their heels, and the waistline eventually (ca. 1830) returned to the natural level. (There are a number of answers relating to changes in men's fashion around this time in my profile, but feel free to ask more specific questions about this or about the changes in women's fashion!)

The main impact of technology on fashion was in textile production: weaving and printing were of course some of the earliest industries involved in the Industrial Revolution, and over the course of the 18th century, cotton went from a very high-end fabric to a fabric that ran the gamut from high-end to almost rock-bottom as the production costs (and quality) could be trimmed and trimmed and trimmed. This manifested in two significant ways. One was in cheap printed cotton: in, say, the 1730s women could only wear cotton gowns if they were quite well-off, but by 1800 a poor woman was as likely (or more likely) to wear a cotton print dress as she was to wear one of coarse wool. The other was in white muslin: likewise, early in the 18th century a sheer white cotton was difficult to produce and therefore quite expensive, and by 1800 the price was more reasonable, satisfying the fashion for classical fashions.

One can see drawings/pictures of men sporting excellently kept beards and hair. Did it take much effort to keep it?

It depends what you mean by "much effort". Did men roll out of bed in the morning looking like that? No. It says in the 1833 Toilette of Health, Beauty, and Fashion:

The bushy, shock-like manner of covering the forehead with a profusion of hair, even in curls, as worn by the loungers, dandies, and mimic militaires is revolting to the countenance of a man; and not only do such effeminate appendages subtract from youth, aspect, and manliness of appearance, but frequently leave us in doubt of the gender of the individual, with other impressions derogatory to the honor, sentiments, and taste of Englishmen. We mean not to imply that our heads, as well as those of the ladies, ought not to come within the proper sphere of the artist, and indeed nothing is more becoming and proper; but we declaim against the introduction of foreign locks, curls, and fripperies, which serve to baboonize and obscure, rather than to ornament and illustrate the face of man, however whimsical or parsimonious nature may have been in the moulding of it.

The Toilette gives a number of recipes for hair and beard oils, tips for shaving well, and other related cosmetics and procedures for men alongside the advice for women, because men did groom themselves then as now. I don't know that technology changed this: someone with more pharmacological knowledge than I would have to look at the recipes and see if the ingredients are all natural or if they're the result of mechanical processes not invented until the end of the 18th century.