Another helpful thing to think about is which colors look good on you. Read about seasonal color palettes and also spend some time holding colors up to your face. Go to a store and try on every color you can, which ones flatter you?
Not everyone does it this way, but I found it helpful to create a color capsule. Decide on a couple of neutrals and several colors that all work together and look great on you. Mine for example are grey, cream, sea blue and plum. I don't always buy items in those colors, but they're the building blocks.
Take a day and go through your closet and drawers. Try to figure out what you have that fits and flatters you. Be ruthless! If you'll be left without clothes keep the passable ones, but at least make a list of what you'd like to replace over time. Try to figure out what you don't have which would stretch your closet, maybe a pair of tall black boots or a white button down shirt.
It's good to have an idea of the styles you like, but I think you'll develop that over time. It's hard to know which way is up at first, but once you figure out the basics you can build on that.
