Turn on lighter.

Hold needle over fire (be careful not to burn yourself!) until it turns orange

Turn off lighter

Press needle to the nail. Start on the side you normally wouldn't paint if painting your nails; this is to insure you won't be poking your needle through your actual flesh.

Make sure it is at least 1mm away from the tip so your nail doesn't crack.

Apply pressure and twist until the needle is in.(it is good to push it all the way in and back out again, to open up the hole a bit more)

Slide your needle in and out a few times until the movement is smooth and easily done.

Remove needle and go in from the other side(into the hole you just made), and slide it in and out until the movement is smooth [again].

Take out needle

Repeat the process with the thumbtack(there is no need to heat up the thumbtack; this process is to widen the hold so that your charm will fit in better)

Remove thumbtack

Try your charm on; make sure it fits into the hole (if it doesn't fit, you may want to use something a bit wider to widen the hole even more.. just remember that if you get too close to the tip the nail might crack)

Buff your nail so there won't be any rough edges where you pierced your nail.

Paint your nails (if your nail polish gets stuck in the hole, just use your needle to open the hold up again--it shouldn't be hard since you widened it with the thumbtack.)

Wait for nails to dry completely.

Apply charm with a pair of pliers.