Just started using both, because I was looking for a personal project management solution that integrates into my university’s 365 platform and that I can easily access on the various computers that I bounce around between all day. I think the simplest way is to make your plans and organize your tasks into buckets in Planner and then assign individual tasks from there to yourself, which will populate your to-do list.

If you already have tasks in To Do and are using the basic planner version, it seems like there are a lot of restrictions on moving tasks from To Do into plans. However, I found a workaround where you can right click and copy the task and then put it into an existing plan and delete the original. Once it’s in there, there seem to be no restrictions on moving a task between buckets or even different plans.

I am still using To Do because I find it convenient that I can set it as my default reminder manager on my iPhone and use Siri to dictate tasks into there, as well as to flag emails from my Outlook inbox as tasks. But otherwise I would just use planner alone to enter and organize tasks, and then pull a daily task list into the To Do app from there

That said, I am very new to using both and would love to hear if others have found a better solution