Just another thing I hadn't run across yet in the couple hundred posts I've read on here. Before I learned this, I didn't think it was possible to Prusik both ends of a line onto other lines (or the same line) because once you've tied the first Prusik on one end, you can no longer pass the line through itself. However, I've attached a way to tie a Prusik "in hand" that allows you to make a Prusik in the line without having access to the other end. The pictures only show one wrap around the thumb and index finger, but you can take as many as you want to increase the gripping power of the knot.
Another way to do it is to have a small stick to tie the first Prusik to. Then, you can still pass the line through itself for the second Prusik and then transfer the first from the small stick to whatever it's supposed to go to.
Of course, you can't put the second Prusik on anything if you don't have access to it's end since you have to transfer the finished knot onto it.