Foolproof ???? Not that I know of

But here are some tips

http://straightrazorpalace.com/works...wers-here.html

Use that sticky it really does have a ton of info

This is still the way I do them see post #7

http://straightrazorpalace.com/works...r-restore.html

The rubber cement is still the easiest I have found to work with...

Note the scales have not been rounded in when I drilled that back in 08 now I chamfer the edges first, then drill, then round more...

Looking at the imaginary center line in the scale, if you are going to make an off center hole, make the mistake to the top, not to the bottom, but try for center...

Watch the size of the hole, you can go 1/16 then round out to 5/64 (as Mike already mentioned) assuming you are using 1/16 rod for pins...
two reasons for this,
1. the rod isn't perfect
2. it gives just a touch of play in there for adjustment