For making textures is there a way to draw directly onto a sphere? like any programs that allow you to draw directly onto a sphere? for making heads and such.

I think mudbox may allow you to, but, dont take my word for it, since i have never used it

Blender lets you.

If you want to do that you are better off drawing in 2d what you want the head to look like from the front then projecting it on to a sphere in blender. Blender is nowhere near as good as PS or GIMP for editing images IMO.

Ah, I tried blender but I couldn't get used to the controlls... I guess I'll stick to 2D on Paint Tool SAI..

Pretty sure it's also possible on mudbox with a little program added to it. Should be somewhere in nblx's tutorial about advanced texturing

Mudbox isn't exactly free.. Its also pretty pricey.

Mudbox and Blender are the only options I know of.
You just have to download the tori model rigs and import them to paint onto it, but yeah check out tuts if you want to do it, it's a bit more complicated.

Also, If you don't want to pay for Mudbox or Blender, I guess you're stuck with regular 2d mapping.

There is a free student license for mudbox which you can use, just google it and it should pop up somewhere. I already did it myself to test mudbox out a while back and it was fine. (Also the tori rig for Mudbox only sems to work with the 2014 and above versions of mudbox so be careful on that bit)

You can use Photoshop to do it, but I find it extremely weird and it often crashes when rendering the texture back to 2D.

How do you render a texture back to 2D?