I take a straw section, fold and secure one end, then stuff the vaseline/cotton in with a wooden skewer. A 2" section will hold a bunch of cotton stuffed hard.

To use I simply cut the straw in half, then split the straw and remove the cotton or you can sometimes pull the cotton out with a stick or knife point. Fluff it up and spark it. This is about the best way I have found to keep vaseline/cotton tinder in a pocket kit.