I think you have all the advice you need written above Mike, so this will probably be a bit redundant, but I'll put my routine in as well since I have a moment.
1st, I start with standing behind the ball to get a general line the ball will follow to the hole based on the terrain. Let's say I guess that it is about a 6 meter putt with about 30cm left-to-right break, and slightly uphill (playing 7 meters). I'll then stand off to 1 side or 2 to get a better read for the up/downhill slope. Then, I'll stand behind the hole, to get a read for a putt from the hole to my ball, and see if I come up with the same reading going the opposite direction, which would be a 30cm R-L breaker, downhill (5 meters).
If I don't get the same readings, then I'll take an average between both reads if there isn't enough time.
Let's assume I got the same readings both ways. Back behind the ball, I'll pick out something on the green about 1 foot that is in line with 30cm left of the hole. usually it is a blade of grass, but sometimes it is discolored grass, or other object.
Line up the line on the golf ball to roll over the target 1 foot in front of my ball, then set up for 2-3 practice putts near my ball to gauge distance. Set up for my putt to roll the ball over my target, make sure the putter face is square to the target line, then mimic the swing motion for distance. It should be pretty close if my putting stroke was good.