Try starting with about 50% factor as a starting point, then gradually a little less as you are further away.
For example, a 10 footer try hitting it with 5ft power. A 20 footer go about 9ft power. 40 footer about 17ft power. Putts under 10ft I like to be more aggressive. Same general rules apply with severe uphill/downhill - add a little more for the former, subtract for the latter.
Hope you're not playing Merion 🤣 good luck!