Here are some ways to use the words individually:
* Rain: The *rain* was heavy, causing the river to overflow.
* Reign: The queen's *reign* was marked by peace and prosperity.
* Rein: The rider pulled back on the *reins* to slow down the horse.
If you're looking for a sentence that uses multiple words, you could try something like:
* "The *rain* poured down, but the rider held firm on the *reins* and continued their journey."
* "The king's *reign* was marked by a lack of control, as though he was struggling to hold the *reins* of power."
Remember, context is important! The best way to use these words is to choose the one that fits the meaning you want to convey.