You should be documenting the training.
Couple of suggestions for good documentation:
You could do it the same way as a Part 141 school. Tell your student to get the Jepp folder (ASA makes one also) or whatever, and record the lessons the same way.
My own system consists of two (or maybe three)
parts:
1. I use a 2-part lesson record form I created for each lesson. The form is essentially a listing of PTS tasks with boxes next to them that you can use for simple check-offs or grading. Both I and my student sign it to acknowledge the training received and we both keep one copy as a record. This way, we have a comprehensive record of each lesson showing continued evaluation of maneuvers while reserving the student's logbook for things that have to be logged under the regs as requirements for the certificate or rating. For example, if a lesson focuses on slow flight and stalls, that's what will appear in the logbook. But the lesson record will also show that radio communication, basic straight and level flight, etc were also evaluated. (BTW, my logbook entry for the flight only contains the student's name with no maneuvers mentioned.
I'm pretty sure that there's at least one company that makes something like this commercially. Or maybe I should start marketing them.
2. I use a syllabus that consists of a list of tasks that need to be covered in each lesson. It's in table format with a column to enter when the task has been logged. It's less for tracking progress than for ensuring that all tasks that the FAR require be logged are logged.
3. There's a third piece, but even I think it's overkill. It's a spreadsheet based on the Jepp folder. The one thing I always liked about the Jepp (and similar) folder is the ability to see a student's progress at a glance. I can do it with this.