Sometimes I see things like this:
*July-Nov drum line
*Nov-Dec Concert music
*Jan-Feb Solo and Ensemble
*Feb-April UIL concert music
*April-May drum line for next season
IMO percussion students should be working in 4 overlapping "seasons":
*all-state/region auditions and marching band in the summer/fall
*a solo, an ensemble, winter concert music in the fall/winter (and the state etudes as necessary)
*indoor show, a solo, ensemble, and UIL or other concert music in late winter
*concert music, solo and ensemble, and drum line music for next year
This way we're almost always playing concert percussion either as a solo/audition or in a percussion ensemble. When appropriate we also work on drum line for marching band or indoor.
It takes time to train the students to work outside of class (practice) to get things done and the material has to be easy enough in the beginning for them to get it all (and they need to come from MS with an education in percussion not just standing in the back of the band class) but I've found it to be effective.
Plus the kids are happier when they learn to love and enjoy all aspects of being a percussionist AND if they want to go on and study they have a solid foundation to build on.