practice!
i always had trouble with it overflowing when i finished the roll, so i fold the papers over so there's about a 1/4 of an inch less paper on one side...dont fold it in half....so it rolls evenly without spillage. folding it then filling makes a nice trough for the maryjane to sit, makes it stay in place. this works best with 1-1.5 sized papers, not the french size