I put my 3mm tap in a 7.2v reversable cordless drill, keep the tapp well lubed and clean the tap constantly with a brass brush. Barely pulling the trigger, when it stalls, back it out, clean/relube the tapp, blow out the hole with pressurized air and go again. Haven't broke a tap yet, wore a few of them though.
That tap guide you show Jeff looks to be the cats meow, very simple & effective.
