What I did to help me drill, was to buy a Uni-bit or sometimes called a step bit.
I used painters blue masking tape on the door where I was going to drill, since I was using the tape, it was easy to make marks on it. Then drill a small pilot hole, change to the step bit, and drill slowly until you get the right sized hole.
It left a nice, clean, burr free hole. Look under my profile for pics if you like.
Hope this helps.