90% of riding is hustle. The harder you run, better job you will do. Remember, you're man down because the other team has a goalie to help clear, and the only way to overcome this is to hustle more.
Never give up. If a defender is past you, do not stop running. If anything happens to slow them down, such as a teammate sliding to them, you could catch up and check their stick from behind.
Always cover the goalie hard when he comes out of the crease. The goalie is only allowed to stay in the crease for 4 seconds. After that, when he runs out of the crease, he is open to checks. As a general rule, goalies are not good at protecting their stick, so this is often the weak point that you should look for.
As a defender, if your team is riding, be sure to lock off your attackmen. If you don’t do this, the other team could easily “cheap” the ball down field to the attackmen for an easy clear.
Cover the players furthest downfield first. Doing this will prevent an easy clear and guard against the other team getting a fast break by passing it past your entire team.
While playing defense on the person who has the ball, make sure you run with them. Don’t stand still and try to take the ball away with one check. This “one-and-out” mentality will get you beat every time. Run backwards and throw multiple checks while running with the player so you have multiple chances of getting the ball back.
Remember that the defense only has 20 seconds to get the ball over the midfield line. If you manage to turn the defenders back and force them to make a cross-field pass a few times, they won’t be able to bring the ball up field in 20 seconds and will be forced to turn the ball over.