I spent an eternity building up the courage to drill the counter sinks for the pop bumpers 
I could picture the drill bit getting away from me and just feeding straight down through the PF, lol.
I mucked about with some scrap timber to get a feel and ended up going about it as follows..
First scored the hole with a sharp 8mm Brad bit and then used an 8mm bit I had ground down fairly flat to finish, all done with batt drill, low speed and very little pressure.