We have set lesson plans for our rec classes that change every two weeks. All rec teachers can suggest skills they'd like included, and seeing as there's only 6 of us, its not that difficult to make everyone happy most of the time. It is also understood (and encouraged) that some adjustments to the plan can be made on an individual basis, increasing or decreasing the level of skills being taught.
We are a very small gym though, and we are definitely organized differently that most gyms out there. Our classes are not separated by ability, only by age. We staff at an 8:1 ratio (this is normal), but each teacher doesn't get a set group of 8 kids. If we had a full class of 24, there would be 3 lead teachers in the gym. We all warm-up and stretch together, with one teacher leading and the other two assisting during that portion. Then we break the kids up into three groups and go to our first 15-minute rotation. We group the kids based on age as well as ability and these groups sometimes change week-to-week. When its time to switch areas, only the kids switch. So, for example, this week I'm teaching beam--and I will teach three rotations of beam, and get to work with all 24 children. While I have a set lesson plan, I also differentiate what and how I teach based on the group I have. One station this week was various ways of getting across the high beam. My less-experienced group might have a focus of walking across the high beam with no help and good posture going forward, backwards, and learning the difference between coupe and passe; my more-experienced/higher level kids might be working on perfecting their form while walking on releve, straight leg kicks forward and backward, tuck and split jumps, and teeter-tottering (or handstands) starting and finishing in a lunge. Basically, we work our way through typical progressions.
This way works really well for our gym because of how much we work together and the way our classes are organized.
Off topic a bit, but I really enjoy how we do things. I know the staff very well, because we have to constantly interact, and I know all the kids--not just 8 I am responsible for that hour. We are also able to separate kids who have difficulty working with each other (or who work together too well--but only to cause mischief, lol) and pair up kids who complement each other well. Just something to think about as you start to plan your gym, BarCoach