Pick a Fake Play
There are many fake plays that can be done and make sure that you pick one that you have practiced well and the other team will be least expecting. Often this play is going to be related to getting the work done through your weaker suit when the opposing numbers expect a push for strength. If you are good at running the ball, an unexpected pass can do the job.
Spread the Word
Let the offensive team know that you will be executing the play. There is no need to yell in order to let them know and politely get the word to them. The best time is to let them know in the huddle.
If you intend to pass the ball instead of running it, make sure that you act completely in the manner when you are going to run it. Make no sudden moves that can give it away. Your offensive linemen should continue with their regular routine. Similarly, the quarterback should continue with the same routine as he does when running the ball.
As the quarterback moves back to hand-off the ball, the running back should perfectly fake a grab on the ball. Make the other team think that the ball has indeed been passed and let them have all their attention on the running back.
As soon as they move on the running back, make your move and pass the ball to the open receivers. Make sure that your cover is at no point broken and you pass only when you know you can find the receivers who can in turn make a successful play. This takes a lot of precision and that can only come with practice.