Personally, here's how I do it - with good results . . .
FIRST: I make certain point faces are parallel and square to each other - equal distance across from each other. I bend, pry, tap with hammer & punch, use a needle nose, whatever . . . just get the faces as straight as possible. If you don't, they are just barely touching at one point - and you may not get a good ground, more arching of spark, more pitting of point's faces, etc . .
NEXT: I check my Points Gap on both the "Narrow" and "Wide" lobes.
Magneto Points = .015 to.016 gap (.018 new set)
Cone Points = .020 gap (.022 new set)
If they are a new set of points, I add a couple to compensate for the fiber block wearing.
NOTE: If the gaps are different on each lobe - I will "true up" the shaft with a small brass hammer or a punch with tape on the end . . . (see below) Otherwise you have (2)different points gap setting for each cylinder - which is lame. I think my motors run better with equal point gaps.
I just lightly tap the shaft opposite side I want it to move. Most of the time it works. Sometimes the shaft won't move much. Sometimes it's off quite a bit. If I can't get the shaft to move, I'll split the difference from each lobe and set my gap at that . . . kinda in the middle. Example: .022 and .018 - I'll set it around .019 or .020 - ( a shaft with .005+ run-out needs trued )
Spark Plug Gaps
Magneto = .020-.025
Breaker Points = .025-.035
The more powerful your coil, the more you can open up your plug gap. Most electronic ignitions can jump a .030 or more . . . really get that flame to travel. The wider gap, the more your coil will "strain" to jump that gap, possibly damaging a stock coil? I usually run what the H-D Service Manual recommends. Check your cone points every 10K miles. Magneto Points last longer. I've had the same sets of points in my magnetos for about 10 years now - and they all still look good.
ALWAYS grease your cam lobe (fiber block)
With advance weights:
ALWAYS set your timing with weights in advanced position ! Use a screw driver or needle nose to advance your cam to the stop in the direction it turns when engine is running . . .
5 ohm coils = Points Ignition
3 ohm coils = Electronic Ignition
(You can run a 3 ohm coil with points, you just risk burning your points a bit faster over time . .
See you on the road !