As a rugby player, you must always be ready to receive the ball.  Let the ball carrier know where you are through eye contact, shouting, or even body language by having both hands out.  You should be t meters behind, and 5 meters diagonal from the ball carrier, called the “5 x  5” Rule. 

The catcher needs to keep his eye on the ball at all times until he has it firmly in his grasp. As a warning though, thinking too far ahead about what you will do with the ball can cause you to drop the ball, or even knock it on (a knock on is a penalty in rugby).    It is up to the catcher whether or not to catch a bad pass, but if you drop it you get the penalty, on the other hand if you don’t catch it the opposing team might.

When catching a kick, you must shout and call for the ball so that your teammates know, to avoid any possible collision.  Make your arm into a basket against your chest where the ball will fall.  If you see an opponent also trying to get the ball, you must jump for it.  Also, when picking up a bobbing ball, you must do your best to judge the uneven bounce to avoid knocking it off.  If in doubt, fall on the ball to create a ruck and give your teammates time to reinforce you.