What I recommend that you have on hand is the following:
Bare-Metal Foil (duh)
X-acto knife (or any hobby knife)
Plenty of extra blades
Toothpicks
Scissors

Inside the Bare-Metal Foil packet is a single sheet of foil and an instructions sheet. The instructions recommend that you take a #11 X-acto blade, run it along a sharpening stone, then begin cutting the basic shape of what you need off of the foil sheet. Hogwash. I used scissors to chop out a tiny portion that is a lot easier to work with, and I did not spend a few minutes grinding the edge of my blade before diving in.
What I set out to foil is a Mercedes emblem on the back of a 300 SLR, (just ignore that the car is pink :whistle: ) so I cut out a square of foil (with scissors) about twice the size of the area that I planned to cover.

I then cut out a rough circle that is again, larger than the emblem that I ultimately wish to cover. To do so, I merely ran the blade along the surface of the foil. It is so thin that you need not press to cut it. As the instructions state, simply allow the weight of the knife to cut the foil.

Peeling the circle that I cut out off of the paper backing wasn't necessarily hard, but not easy either. I just slid the edge of the blade under the foil and began carefully peeling it off. The foil likes to roll, so take time to stop and smooth it back out as you continue lifting it. Once I had the circle off of the paper, I placed it over the emblem.

Using a toothpick, I began pressing the foil against the emblem, taking care to mold it in to the details. It is possible to tear the foil while doing this, so don't put too much muscle behind it. Take time and continue rubbing the foil in. I don't suggest using anything that has too much of a point on it as that is sure to tear or cut the foil. A toothpick seems perfect for this task.

Once the foil was hugging the details of the emblem as best as I could get it, I turned back to the X-acto blade and carefully cut away the excess. Don't worry about ruining the paint job of the surrounding area. The foil does not take much pressure to cut, so you are basically just tracing along the edges with what happens to be a razor blade. The foil will cut. Even if you do go a bit heavy on an area and cut in to the paint, chances are that you won't be able to see your slip-up as it will be along the edge of where the foil meets the paint. Basically, this stuff is idiot proof!
The majority of the time spent applying the foil was spent in this trimming stage. Don't be afraid to swap to a new blade or two during this process. The worst thing that can happen is that your blade could go dull, catch on the foil, and rip it where you don't want it to rip. I cut a little bit away at a time until I was left with what looked good enough to me.

The only downside that I could find to using the foil is that my camera doesn't seem to like focusing on it. If that's the worst thing that happens, then it was money well spent. I had planned on painting this emblem, but it turned out to be much easier to just foil it. Had I painted it, I would have had to worry about runs wrecking my nice pink paint-job. No such worries here.
So don't feel intimidated by the foil. It's actually pretty simple to use. In fact, this was my first time ever using the stuff! :D