Typically, I edit¹ along the lines of:
or, as @SavvyUser mentioned in the comments@SavvyUser mentioned in the comments, defrobnicating the bellflange might be a slightly more elegant approach.
That is, if the approach is a slight or moderate improvement on my own answer.
If it's an entirely different or novel approach, typically I'll encourage them to post it as a separate answer proper, and upvote them if they do. If they demure, or if after a reasonable amount of time they have taken no action (reasonable varying with the norms of the specific site and tagset), I'll revert to strategy 1.
¹To call it out specifically, I personally prefer to integrate new information directly into the answer, in the most appropriate section of the prose, rather than tack on addenda in the form of "EDIT: better yet, defrobnicate it!"