I don't have exact measurements but I first cut my brown craft felt piece into thirds, length wise. Then I cut each of those pieces in half. This gave me SIX pieces, which would turn into SIX pencil brooms off of ONE craft felt piece.
Once each felt piece was cut out into a smaller rectangle, I took my scissors and started to cut strips along one side. Not too high up though because you don't want to cut your rectangle into small pieces. You will want to create a fringe on the long side of the felt piece. Repeat for each piece.
Next, I took my cut felt piece that I just created a fringe on and started rolling it tightly around the unsharpened end of the pencil, to create the bottom of the broom. Once it's rolled, it will start to flair out a bit.
To finish it off and secure everything in place, I then took a small black rubber band and slid it onto/around the rolled felt. On this step I added a couple of rubber bands to really secure my felt. My suggestion is that the more bands you add, the tighter it will become around the pencil. You could of course add some adhesive to the felt but remember, you want the receiver to be able to slide off the "broom" part and be able to use the pencil afterwards.