The phrase "watch-it" is often used as a warning or caution to someone. There are several synonyms that can be used in place of "watch-it". One of the most common synonyms is "be careful", which is a simple and clear warning that indicates that someone needs to exercise caution. "Watch out" is another commonly used phrase, which can be effective in alerting someone to a potential danger or hazard. Other alternatives include "look out", "mind your step", "proceed with caution", and "be on your guard". Using different synonyms for "watch-it" can help to convey the same message in a variety of different ways.