You know what it's like when you are piercing something complex and you manage to break the last of your smaller drillbits? In the evening? On a Sunday? This may help...

Take a sewing needle. Chunkier is slightly better, but it has to be a nicely springy one (so some of my very soft harness needles are utterly useless for this). Using pliers, snap the eye in half. Grind the end flush on a fine oilstone; holding the needle at around 15-20 degrees, grind a flat to fractionally over halfway through the needle at the eye end. Then turn it over and grind 2 facets at about 45 degrees to make a sharp point.

Bung the needle - sorry, artisan crafted drillbit - in your bowdrill and drill away, leaving holes just big enough to fit a fine sawblade. I've gone through about 1.6mm sheet using one of these; I have to confess I haven't tried it with the Foredom.

There's other methods to make drillbits that are easy too - this one is just so quick & simple that it is something of a no-brainer.