You probably saw it just to your right-----------------------------------------------------------> titled "Putting Tips" in the FAQs, where you can also find a ton of other info. You can also use the Search box at the top right for anything else, or post here with a question.
As for a "magic formula", I call it "feel".Imo, if your using your judgement of the wind, ball lie, up or down to target, where the ball will land, green speed, and how the ball will react to all these factors, why would you want to have the power you hit the ball Pre-calculated?
Practice a lot and you`ll get a feel for it. Also, be aware of how your ave. is figured. If you play a lot of 9 hole rounds, it will generally bring your ave. down quicker than you expect and you`ll become a master sooner than you want or should be. GL and enjoy!