The best formula is to play in practice mode. Then play/putt on the green in those awkward but likely to land places then take notes of elevation and distances required on that particular green.
For example, I have done this on RSG 3rd pin par 3. Here, it is likely a lot of people come up short - including myself - quite often the ball rolls back down the green leaving an uphill putt with differing elevations ranging from 3 feet to 2 feet to 22 inches etc.etc.
So in tournament mode I say distance x 0.75 then add the necessary yardage from my notes I had made for that particular elevation whether it be 22 inches or 3 feet. I now play the uphill putts to perfection on that green .......works every time!
REMEMBER TAKE NOTES! .....THE PROFESSIONALS DO SO WHY NOT YOU?