Sleep on it is a phrase that is often used to suggest that taking a break from a decision might help in making a clearer choice. The phrase means to think a decision or problem over, usually for one night, and make a choice after getting some rest. However, there are many other ways to express this sentiment. For instance, consider using the phrase "mull over" or "chew on" to encourage contemplation. You could also suggest "letting it simmer" or "marinating" on the situation for a bit. Other phrases to use instead of "sleep on it" include "have a ponder" or "allow it to settle." Ultimately, the goal is for individuals to take their time and think carefully about decisions before making them.