When receiving the kickoff, if the opposition has a player within range of retrieving the ball, try to move a player next to the ball (preferably in front of) the ball BEFORE attempting to pick it up. This is a safety measure, and some teams need it more than others. As a general rule if your retriever is ag3 or less and doesnt have sure hands, you should take care.

Unless your ball carrier is VERY unlikely to fall over, try not to use him to blitz or block - it's usually a risk you don't have to take, and because he will drop the ball, the opponent will just be able to pick it up, and then you've got to defend when your team is set up to attack.