A service to any Chaliceblog readers who are currently or might in the future be stranded on a desert island.
For all of these, you're going to want to find an area that's as open as possible, preferably with no trees over it. Mostly, this is to keep the fire from spreading, but it could also help you get rescued.
Try to get some stones and make a fire triangle. The stones help keep the fire from spreading, as well as insulating and protecting it, and the triangle is the international distress symbol.
Now, a few methods for getting the fire started.
1. The "plane crash" method
Get a nine volt battery, some tinder and a bit of steel wool. Put down the tinder. Put the battery on top of the tinder. Put the steel wool on top of the battery, touching both terminals. Stand back.
2. The "nerd" method
Use your glasses to focus some sun against some tinder.
3. The "I was a boy scout" method
Pull the flint and steel you always carry with you out of your pocket. Use.
4. The "McGyver of the Woods" method
Get a sturdy, but bendy stick and some vines or a shoelace. Tie the vines to one end of the bendy stick and then to the other, forming a bow.
OK, I'm boring myself already explaining this. Here's a detailed explanation.