have your own style in dressing.
but don't ever turn out to be a fashion disaster and attract
attention wherever you go 
its the wrong kind of attention you'll be attracting.
the Men's Health magazine actually has a section on fashion.
from there choose the appropriate one for you.
but let me warn you the clothes advertised are always rather
slightly steep, especially if you're not working.
an advice from me is don't dress like a 30 year old man
when you're only 20 