Have a look at a few of the traditional styles first.
50's Americana, Nordic, traditional Japanese - the advantage of these is they are essentially timeless (never in or out of fashion) & will also be more likely to look palatable when you get older (at least in my view anyway).
Skulls can work, but as a warning a few my friends who have had them regret it, as they came to think it was 'too dark' for later in life once they had moved on in life - just a consideration. Personally I avoid any bands (may end up as paedophiles for all you know) things with transitory meaning (what you value today will most likely not be the same in a few years).
Anyway, enough rambling from me, good luck with what you find.