Open up gimp, make a 128*128 file. Draw something on it. The head will appear on toribash like this:



Save the document on your desktop as head.tga (head being the file name and .tga (targa) being the format).

1) If you have a head texture, go on Torishop - textures and upload your texture. It will appear on your toribash characted after a few minutes.

2) If you don't have a head texture, make a new folder under \Toribash\custom named "test", put your head.tga in there, go to singleplayer and type "/lp 0 test". You will then see the head.

As for how to draw a nice head in gimp, that's completely up to you, there are many tools and functions to use. If there would just be one tutorial for it, everyone would be making heads that look exactly the same.