Combining textures into one image.

I have two (and often more) textures I want to lay on top of each other in order to create one single texture. Basically layering a Skin texture, Shirt, Pants, and Belt textures (and more), so the entire character’s textures are on one single image.

What might be an accurate, efficient way to do this in Unity Indie?

Short of writing your own shader (See Strumpy’s Shader Editor, it’s free), you might use GetPixels/SetPixels to composite them into a new texture. You could even save that new texture to a file, effectively caching it. Since you wouldn’t need to do this every frame, only when choices change, it should be fine performance-wise.