Be yourself and create your own style. I find that layers work best, mixing solids with prints and different textures. For example, a solid v-neck tee with a print long-sleeve button down and a soft knit scarf, with simple jeans, a leather belt and cute boots. By mixing the layers you have a thousand more outfits than you would just wearing certain tops with certain bottoms.
Have some basics - tops and bottoms that can be layered over and don't have much of a pattern or color that would exclude a lot of other colors/patterns. (Soft blues, blacks, tans, greys, and whites are good basics.)
Then some more trendy layers, with cute patterns or colors. (Plaid, polka dot, pinks and reds, stripes, open knits, etc.)
Finally accessories like scarves, shoes, and purses that will match a variety of outfits, and maybe a few more unique ones. For example, get some boots in a simple soft black leather and they will match more clothes than the orange-and-pink sneakers will.
I be stylish by not wearing t-shirts and sweats every day (aka "lazy clothes"). Along with this I make sure that I like what I am wearing and that I'm comfortable in it. I also make sure that what I'm wearing describes me as a person because your appearance is one of the first things a person sees you as. Style starts with you :] Be yourself and have fun.
here's what I do: be myself. and go nuts with my clothes. as much as people bully me, I still stand strong with my style and sarcasm. the style is mine, and the sarcasm can make people shut up quickly. then I just walk away with all my sass. I have a certain way I like my makeup, the other girls layer it on heavy, I don't. some days, I don't wear any at all, others I'll just put on some lip balm and eye stuff.