I know there are some other make-up rolls on here, but they just weren't what I was looking to make, so I decided to make my own! I also made a matching cosmetic case out of the leftover fabric.
To begin, decided how many brushes you'll need and how tall the highest one will be. I had just purchases a set of 12 brushes, plus I wanted to leave a little pocket for some of my shorter bare minerals brushes. You'll want the width to be large enough to hold all you're brushes, i believe mine was about 1/4 yard. For height, you'll need it to be at least twice as long as the tallest brush.
Fold up the bottom half to decide how high the pocket needs to come up the brushes. Pin only to the lining, letting the outer layer unfold so that it is out of the way, that way the seam of the pocket will only go through to the lining. This gets a bit tricky, but pinning is definitely the key to keeping all the layers in order.
This step could have been done with step 9 to avoid seeing the seam, but fold your ribbon in half and sew to the side. I went back and forth with the sewing machine a few times to make sure no seams would ever come undone. The ribbon has to be long enough to wrap around the roll and tie in a bow. I sewed mine on the side with the bigger brushes because I figured it would be easier to roll with the smaller brushes on the inside, big brushes on the outside.