Well, in my case, I had a rough idea of what I wanted. Generally, though, you just have to go for it. If you go to a good salon, the stylist will do a free consultation with you before a cut to decide what you want to do. They will take into consideration things like your face structure and shape as well as your hair type. This kind of service costs more, obviously; in your area you're probably looking at spending at least $75-$100 for the cut (based on what I've read in Women's Health; haircuts in your part of the country are apparently outrageously expensive). If you're really looking to change your look and you don't know where to start, that is what I would recommend, because they will consult with you, and often if you don't like the cut, you'll be able to go back and get it fixed free of charge. You really do get what you pay for with haircuts. Ultimately, though, you just have to take the plunge and chop it off; I admit that yesterday I was so impatient to have it done I went to Supercuts.
Surprisingly, she did a good job--usually that isn't the case as I have 1) a lot of hair and 2) it takes a lot of time to cut, something people at Supercuts aren't usually willing to do. It's so freeing! I really recommend short hair.
As for wearing makeup better--how do you wear your makeup now? What do you wear? What products do you use?