When it get to the last bit, I sit on a chair, couch, cooler, whathaveyou with the wheel on the ground vertically in front of me, the last bit of unseated bead facing away from me, at the top of the wheel and just wring the tire on with both hands. I just keep wringing even if it doesn't pop on right away. On tough tires, I might have to wring 20 times or so 'til the tire warms up and gets pliable enough to get convinced of where it needs to go.

Works for me every time. It would probably be difficult on deep aero rims, however.