Off the line, without speed burst, immediately juke right then left. The CB will be fooled. Speed burst, run a 45 degree angle to the center of the field, and call for the ball. The CB will either be far away or he will be behind you, and you will catch it almost every time for an easy touchdown. This also works during games, but it takes some of the fun out of running routes. Instead of right then left, do left then right and catch the ball running up the line for a big gain.
For an easy touchdown or first down, make sure that you have a fast QB or this might not work. When it is third down and you need a first down, call a pass play and the defenders will lay off you slightly. When you see an open gap, run in that direction. Run in a 45 degree angle when defenders start to get close. When a group of defenders start to approach you, make a QB dive so that you cross the line to get a first down or touchdown. This also works well in Superstar mode. Do not wait too long or you may get sacked.
To score easily, get a spread set with two receivers on one side, then do a hot route on the inside receiver and press the Right Analog-stick in the opposite direction of the quarterback, making an outer slant. This should help you score or get a lot of yards.