Pick one day per week as the day when all players on your team wear one light colored sock (on the non-dominant foot) and one dark colored sock. During a scrimmage all players must play the ball only with the non-dominant foot (light colored sock). If a ball is played with the dominant foot an indirect free kick is given to the defending team. The two sock colors make it easy for the players and coaches to see which foot is being used.
Other ideas for improving players’ non-dominant foot skills:
When practicing ball skills on your own, such as dribbling through cones or passing and receiving against a wall, do twice as many repetitions with the non-dominant foot as you do with the dominant foot.
Conduct a scrimmage and put one or two players on their non-dominant side of the field. So righties go on the left side of the field and lefties go on the right.
Do this with only a few players at a time so that the natural rhythm of the game is not diminished.
Play soccer tennis where only the non-dominant foot can be used.
Play a regular volleyball game where only the non-dominant hand can be used to spike the ball or to serve it.
The idea here is to help players become more comfortable with their non-dominant side overall as it will help players improve their balance and make the transition to using the non-dominant foot less difficult
A final note from Coach Snow:
Some players, especially around 8 to 12 years of age will react with an “I can’t” response when asked to play with the non-dominant foot. At this point the attitude of the coach is crucially important as the confidence to work on new ball skills and to overcome the fear of failure can be set for better or worse. The coach must respond patiently by asking the player to say “I’ll try” and then looking for any improvement to praise.