What type of drilling? For a bulkhead? Strainer?
For bulkhead holes, I literally use a standard hole saw core drill bit from Home Depot. They look like this:
The trick is to go slow, apply even pressure and that's that.
I have, in the past, drilled a template from wood to use when cutting through the acrylic. This helps save the pane of acrylic from deep scratches if the bit should buck a little.
If you are talking about smallish holes, for baffle spillways, probe mounts etc, use any decent drill bit you have around. See the spillway/overflow in the
refugium side on this
sump:
Again, take your time, apply even pressure, let the tool do the work, and you should be fine.
D