I have looking on other sites and doing some reading. Many of these resources suggest assigning "soccer homework" between practices. I am a premium subscriber but I have not seen anything on your site about "soccer homework". What is your standing of these assignments?
If you have a high level travel team with highly motivated players, it MIGHT work, but if you have a Rec team, or a lower level travel team, I don't think it will work.
Years ago, like you, I read I should do this and tried it. I couldn't get my players to do it -- they simply weren't motivated enough and had too many other activities going on (swimming, karate, boy scouts, etc.). This is part of what led me to develop the SoccerHelp Program. I realized I had to try to achieve the most possible in practice and to motivate my players to come to practice and games.
I suggest focusing on efficient, effective practices -- try to get 2 hours of practice results in one hour. And shoot for 100% attendance at practices and games.