"Catch it" is a common phrase used to warn someone of impending danger or to remind them of a mistake they have made. However, there are several synonyms that can convey the same meaning in a more nuanced way. "Watch out" can be used to warn someone of danger in a proactive manner. Similarly, "be careful" can convey a sense of concern for someone's well-being. "Pay attention" can be used to remind someone to focus on the task at hand. "Mind your step" can be used to remind someone to take care while walking. Lastly, "take note" can be used to remind someone of important information. Using these synonyms can add variety and depth to communication.