I choose my clothing according to my style and season. Th price doesn't matter as long as you look good and pleasing to the eyes go for it. Yo have to mix and match your clothing so you can use your old stuff.
I choose clothes in colors and materials (blue, black, red, green and wool, cotton, leather) I like. If it has an ugly pattern I won't buy it, likewise if it's cut in a way I think is unflattering. I'm not sure I have a particular style, but I try to buy clothes that will go with a wide variety of other things.