Locate the nearest coupling or connection in the water line. This could be where it connects to the faucet, or where the water line connects to a fixture, such as a sprinker.
Turn the water on at the supply end.
Slowly open the coupling or connection. Use a pair of pliers or adjustable wrench, if needed. After a few seconds, you should be able to see water start to leak out.
Close the coupling or connection and tighten.
Shut off the water at the supply.
Start the water back up at the supply valve. Observe the water line and ensure that it works properly.