I have two images, one for the actual brush stroke (I believe this is the right word? The grayscale image that tells blender how to sculpt or paint something) and one for the brushes icon. Now with those two, how do I create a brush that has one image for the icon and the other for the texture? And then how do i add the brush to the default set of brushes available?
Sorry if this is the wrong section.
To create a new brush, select a bruch you want to copy and press the + icon next to its name. Rename it to your own name. Change its settings as you wish. You add brush textures in the properties window under the Texture settings.
You can’t change its icon without at least some python scripting or even possible only compiling your own custom blender
And remember to press that F button otherwise it will disappear next time you open Blender 
Oi. Alright, never mind that part then.
Thank you.