Do you wax the frame before or after assembly?

I've always put the bike together, got the cables where I wanted them, then waxed the bike. The plan was to do the same on the white PX10 project I'm finishing. But after putting the front brake on the fork and getting grease marks all over the fork legs, and spending 15 minutes cleaning and polishing the grease off, I'm rethinking the process before I move on to final assembly.
If you were to wax the frame first, what areas would you make sure to keep wax free? Would top tube cable clamps have issues clamping firm over a coat of wax?
I use Johnson's in the yellow can, if that matters.