There are a few things you need to know in order to make a repeating brush in Illustrator. First, you will need to create a new layer on the canvas. Then, select the Brush tool and click on the black handle at the bottom of the brush window. Next, drag the black handle up and down on the canvas until you have created a brush that looks like this: Now that you have your repeating brush, it is time to start creating your designs. To begin, simply drag one of your designs onto the canvas and then use the arrow keys to move it around. You can also use the mouse wheel to move it around. When you are finished moving your design around, press CTRL+C (or right-click and choose Copy). Then, paste this copy into a new location on your canvas and name it “Repeating Brush.” Now that you have your Repeating Brush, it is time to start creating your designs!