Hello Everyone!

I'm a newb here on threadless and there's still some stuff I haven't figured out abous submissions. I have a design I'd like to submit, but I don't know how big my original design should be. I'm working in photoshop and it currently has a dpi of over 200, however, it's quite small. It's probably currently too big to fit on a tee, but looks very odd if I take the whole design and shrink it...it gets all distorted...any ideas?!
Thanks a bunch!!