While soaking brushes in water, brush hairs can be permanently distorted if they press against the bottom of the container. This idea prevents that kind of damage.
Clothespins hold the brushes and keep them from touching the bottom of the container. Two vertical wires attached to the container impale the clothespins through the eye of their springs, keeping them in place. Each wire can support more than one clothespin and more than one brush.
Many containers, such as this jar, have a rolled edge, or something to clip onto around the mouth of the container.
Step 1: Bending the Wire
I think I used coat hanger wire for this brush holder. Make sure the wire fits through the eyes of the clothespins you are going to use.
Since the wire is springy, you have to over-bend it a little to make the size ring you want. I used the smaller diameter circle in the hand grip area of a juice bottle to bend the ring that fits on the jar.
Since the wire clips into a reduced diameter area on the jar, the wire ends have to first bend outward, to clear what is above them, before bending up for the clothespins. You need two pairs of pliers to make the bends.