I can't really help you with pre-selected training sessions for the mere fact that I never plan my rides, but I do work within the structure of the training scale. I work on whatever my horse tells me he needs to work on for that day. For example, if it's cold outside and he's an over-excited tense monster, that day we work on relaxation. Lots of lateral work, suppling and bending at the walk. On hot days when he's behind my leg, we work on getting him in front of my leg. If he's reluctant to stretch into the contact, then we do lots of transitions to get his butt into gear. For every training problem, there are many solutions, but there's no way of knowing which ones will work for you and your horse...unless of course you have some video or pics to show?
Maybe, instead of thinking of schooling sessions as set routines, think of them more as a checklist of the training scale. When you first start warming up, think, "do I have good rhythm?" If so, move onto relaxation and so on. If you find your horse is lacking in one particular area, then most people on here can give you suggestions on how to address it. The only other thing I can think of to suggest is the book 101 dressage exercises. Sorry I couldn't be of more help.
You just have to see your distance...you don't have to like it.