Making good textures

#1 Hopefully one of these days I'll get around to doing a tutorial on specific textures. There's really no cut and dry path, per se, with the exception of technology being used. Everyone has a different approach. It's really more experimentation, learning your style, learning your program's capabilities, learning texture balance, creating the illusion of depth, etc. There's tons of online tutorials on texture creation. I'd suggest searching through Google or another search engine when you get a chance. You can also pick up books on it, search over Amazon. Here's a few online tips/tuts I pulled up to get you started.

www.designsbymark.com/
www.phong.com/tutorials/
www.photoshoproadmap.com/photoshop-tutorials-tips/textures-backgrounds.html
www.gamasutra.com/features/20011024/peasley_01.htm

Hope it helps. :)

#2 Well for one, true tileable textures are nice and you get that effect when you use a transform to offset the image half the width and half the height height.

You can also look into applying bump map layer masks to give your 2d textures some depth.

There is also something called alpha layer transparency you could look into. It's how the engine renders transparency and i use that technique a lot.

I'm no expert, and there's a lot of things I would like to learn. It takes time but searching for 'photoshop' and 'tutorial' Google finds tons of online tutorials. I've used those a lot and I am getting better.

Good luck.

*edit* those phong tutorials are like the best. I use them all the time.