I have tried everything (no, really) to get my planning as a teacher organised. I gave up on the black folder a long time ago, have tried inserting stuff into my calendar (failed because it is not easy to see at a glance what needs to be done) and have tried the majority (that I know of) proprietary planners.
This has been a mission for about 4 years now, and I keep coming back to (and comparing everything to) Planbook.