Quickly creating monsters

I have not run a game on here for a while, but with a 3 month medical leave upcoming and retirement a year or so away, I am ready to get some GMing in! The games I most immediately plan to run are Pathfinder 2nd edition and I have the books available in Roll20, so pulling monster in from these are easy. For monsters I am modifying or creating, is there a method, other than creating a character and messing with the character sheet, preferably a quicker method. With the change to PF2, after moving away form the SRD, there are existing monsters from the previous edition that I may need to re-create, plus I will be customizing and creating my own creatures at times.

I don't play Pathfinder, but in D&D 5e I usually pull a monster that's close to what I'm planning to design from a compendium, duplicate it , then modify the duplicate as needed. That way if I ever need to pull in that original, unmodified monster it won't overwrite my custom creation. Edit: Although, for the very few cases where the compendiums didn't have anything close, I did end up just creating a character sheet.