I make all my textures by hand, with a painterly look.

I use a $150 wacom tablet, but you can get an inexpensive Aiptek tablet that is dirt cheap! 40 - 100 dollars, and they're just fine. I used to work for the company that makes Painter, and I switched between both tablets frequently-- aside from being a bit cheaper in construction, the Aiptek is reall good!

If you cannot get your hands on Painter, there is a free version of Deep Paint (not to confuse with Deep Paint 3D) or Gimpshop. Painter has a nice 'make pattern' feature, where the edges 'loop' around.. if you draw off the right side, it appears on the left, good for making seamless textures. Both painter and deep paint have really organic quality brush textures that are hard to get in photoshop/gimpshop.

good luck
Jetpack