Sometimes I sign my art, and sometimes I don't ._.;;; I know I probably should to avoid confusion, but sometimes I forget xD;; Dating the art is important as well, I guess just for personal record if nothing else, but I usually forget to do that too. Whoops. For my paintings, I usually just sign in the corner. I find it hard to sign my oil paintings though, because the brushes are too big and the tips are soft so they smudge DX So whenever I sign my oil paintings, my signature ends up being really big and ugly u_u; I don't know how to avoid that though >: Otherwise for digital stuff, I try to keep it relatively small yet still readable and usually stick it somewhere along the image, so that it integrates itself into the picture.
As for what my signature looks like... I think it needs a bit of work ;o;! I'm not too happy with how my signature looks but eh, I guess that's just the way I sign things.