If you want to use my textures in your pack:
You can use, edit and share my textures as long as I'm credited
You are not allowed to make money with my work
And you are not allowed to use my textures in a customizer (might change in the future, but not for now) or in any othergames not related to Minecraft.
Finally If you like my work and want to support it, donating is a great way of doing it, thanks!