This very simple brush holder has worked out well for me so I thought I'd share my idea with the forum. Starting the DMP method from scratch is costly so here is a cheap and easy way to hold brushes.
See attached photos and then the explanation will make more sense. I cut notches in the sides of the cardboard box and folded the cardboard down. I added a dollop of hot glue on each "brush rest" to keep the brush from sliding. I cut the notches on one side a tad deeper than the other side so the brushes rest at a slight downward angle. I had to weight down the box so it wouldn't scoot around so I used canned goods.
I did my first 6 paintings with just the one holder. When I added more brushes, I made the second holder a bit shorter so the brushes won't bump into each other.