Well, I'm in my mid-20s and quite stylish.
- Collect images that you feel drawn to ... don't pay attention to what people tell you to like ... only focus on what you actually
do like. Eventually, you'll notice recurring themes and items.
- Only buy things that make you absolutely fall in love ... if you don't get the butterflies-in-the-gut feeling, pass. (unless you're purchasing basics... there's no need to fall in love with a plain t-shirt).
- Only wear colors that make you look gorgeous.
- Complement your figure. For instance: if you have a double chin and no neck, you won't look good in a choker.
- Read these books:
A Guide to Elegance by Genevieve Antoine Dariaux and
The Pocket Stylist by Kendall Farr
- Say "no" mercilessly. Doesn't fit? No. Wrong color? No. Not quite you? No. After you figure out what your style is not, you can become more flexible with fun items ... by then, you'll know how to make them work.
With time and a bit of research, you'll cultivate quite an eye. Good luck!