 So you want to make a custom tool, not a problem. A custom tool is a combination of a custom brush and a custom material. To make one, just add a basic paint layer. Set it to whatever material properties you want, then click the brush you want to use with this material and set those settings however you want. Then right click under properties and pick create tool, you're done. If you right click, you will now be able to name it and now anytime you work on a project, you can call upon that tool whenever you need. Hope that helps and as always, I hope you have a fantastic day and I'll see you around.