My history with makeup is more than one might think. I used to work for Max Factor as lead assistant for several artists for Warner Brother Productions on several famous actre-- no, just kidding. I was a drama major for many years. I still know my base is called "Olive," and the next step up is "Leading Lady." I applied makeup and had makeup applied to me for many years and many county and high school productions.
In theater, makeup has one purpose: to expose the flaming queer within. Okay, that was a lie, although being a flaming queer seemed to help, because I never got my makeup as good as some of the DQs did. Its main purpose now is so that people in the back row can still read your facial expressions. Theater makeup highlights the eyes and lips in particular for this purpose. It looks fairly normal from the audience's point of view, but when you look at it close up, it's positively garish, and only the bold and brave like drag queens can get away with it in public.
I have found makeup and the art behind it fascinating ever since. Makeup was worn by some peers growing up. I'll skip the Goths, because they want to shock or express their art, so any makeup tips on them would be missing the point (and Goth makeup is some of the most beautiful in the world, IMHO). When I was a kid, and later into fandom, I have known a few girls and women who obviously missed the entire point of makeup - to enhance and attract. Too many ladies (especially in fandom) who wear makeup, and I hate to say this because it does sound cruel, use makeup like a toddler uses finger paints. I believe this is because as kids they didn't have peer groups that emphasized how makeup should be worn, they don't know exactly why they wear it, and so they carry the same child-born tips "ta look purddy." It's great they want to look pretty (this is any human being's right), but often they think they should emphasize the makeup rather than the face it's placed on. It should not be, "Look, I am wearing makeup!" but should be, "Look, I am gorgeous!"
Get good tips. Not from the angry counter lady at the department store, because some of them look pretty bad. Get tips from someone's makeup you like. Then get some friends to honestly comment on them. I have found one place that's pretty good customer service wise, a place called MAC (a division of Estee Lauder). There may be other places. Good advice would be what colors look good on your skin tone, how to blend, and so on. Bad advice would involve paint rollers and trowels. Also, know that makeup you wear to the office is different than what you'd wear out on the town, or to attract some hot guy. Oh, and replace your old makeup on a regular basis. Remember, you put this on your face, mouth, and near your eyes. Paraffin goes bad eventually.
A lot of these tips come from lessons I learned through anyarm, as well as listening to what Angie and Dana said at MAC yesterday.
I may not wear makeup, but I consider the subject pretty interesting.