I use a Brownells philips bit made for pads. I pre-tap the holes in the wood by running a screw in and out a couple of times but with the least amount of torque possible. With the pad covered nut with the screws in the pad I puch back on the screw, cut a tiny slot in the leather, and use Brownells extra narrow bit to run the screw home. The tiny slot is hard to find but it is there if you want to remove the pad.
bill