Use the proper stick grip and take on the proper hockey stance. To set up for the forward pass bring the puck behind your back leg. Keep the puck in the middle of the stick blade. Rotate your wrist causing the blade to tilt over the puck. In this wind-up position, your body weight should be on the leg closest to the puck.
When making a pass you want to use a sweeping motion. Rather than "slapping" at the puck, begin with the puck on the heel of your stick and during the sweeping motion, the puck should spin to the toe of your stick and off to your teammate. Like shooting, remember to point the toe of your stick at your target at the end of your follow through to increase accuracy.
With your head up looking at your target, release the pass using a smooth sweeping motion (pull on your stick with your top hand and push on your stick with your bottom hand). Keep both hands out away from your body and keep adjusting your aim as your stick moves forward and your weight is transferred to your front leg. After the puck is released, follow through with the toe of the stick pointing at the target.