I've been relying heavily on YouTube videos to learn techniques for creating textures in GIMP. If you're interested in trying your hand at some things, consider watching these videos by user jxtutorials. I've used the tutorials to make wood textures several times now, and noone has complained about the quality yet. :)
This time, I'm trying out the tutorial on making rough stone. Here's an example of something I was able to whip up literally in seconds:
With a little practice, it looks like I can easily control the roughness to the stone as well as make the overall texture have more rounded, sagging areas that appear more organic.
I will spend some time with this technique and post some results to see what I can come up with. I would imagine some version of this would be good for a number of textures. Maybe it'd allow for a good snow texture for winter tiles. Maybe it would make for a good base texture to lay down on cobblestone.
I saw some a nice simple tutorial on making marble texture, too.
I'm not sure if I want to go and make a completely new texture for my caves, if in the end I end up submitting it as a kitbash. I'd like to be able to push totally new material through my own channel and not be dependent on the WWG community. It's too bad TLX is off-limits for folks like me outside the WWG community. I mean, I could do my own thing, but I wouldn't be able to share it. Bummer. Maybe I'll end up being like everyone else - fragment the build systems even more by making my own, or succumb to making chunky pieces that clip together and maybe have it compatible with something like Fat Dragon stuff. I dunno. I guess it's something I have to really start thinking about.