What size screws are you using?
I am definitely not an expert! What works for me is to use a small, 4 flute, carbide chamfer bit with either a 82 or 90 degree angle (imperial or metric screws). I use a helical toolpath that is offset from the edge of the bore towards its centre. Perhaps I'm overly cautious but chatter has never been an issue and it only takes a second per hole..