Hi Tilly,
Could you just clarify that it is "hand drill" and not "bow drill" you mean. I think Rappleby2000 has interpretted your question as "bow drill".
Anyway - a very warm welcome to bushcraftuk. Hand drilling is one of my passions and I have just spent a weekend at the annual meet-up (Bushmoot) and did some tutorials.
I teach on an elderberry drill into a pine hearthboard. The elder is 2nd year wood, harvested green, stripped of its bark and then dried. In an airing cupboard it can be ready in 2 days. The diameter at the thickest end should be between about 1.2 and 1.7 cm.
If we are on the right track then next question please.
Richard, London, UK
If at first you don't succeed - pause, reflect, change something and try again.