I stumbled across a blog post this morning on how to make your own eye-shadow primer out of chapstick, corn starch and liquid foundation. I ran out of primer a long time ago and haven't bought any because I can't find a cheap primer that works well. I made it this morning and put it on before putting on my e.l.f. mineral eye-shadow. After being in and out of the heat for hours it is still in place and hasn't creased!
I first started mixing it with a little butter-knife spreader thing from my kitchen, but then found that a clean finger worked much better because then you can mash the chapstick lumps into the formula. The heat from your finger also melts the chapstick a bit and it just mixes much better.