This is where I bow to the knowledge of others far smarter than I.
I manually crank the engine to TDC and then try and set it to the #1 post on the dizzy. From there, for me it luck - trail and error.
Heck, I have a hard enough time getting the dizzy all the way back in on the oil shaft pin most of the time.
I thought I heard of a trick, but I don't remember what it was.