Good question everyone has a different opinion on this. I have heard nostr:npub1sg6plzptd64u62a878hep2kev88swjh3tw00gjsfl8f237lmu63q0uf63m say that he hopes one day the Zap replaces the like function. What I usually do is Zap 1-21 sats on things that made me laugh or I really liked. 100-2100 sats for best things I seen posted all week. Everyone seems to do it differently but the zaps I do see are usually in the 1-30 sat range.