I have to track daily data for an illness. What motivates me to stay on top of it are the insights gained from the tracking. Being able to go to the doctor and answer questions definitively instead of anecdotally.

We've actually changed the therapy procedures based on the data and then been able to show it was effective with the data that came after.

So think about the insights the tracking will provide you and your doctor, and that might help motivate you.

We use old school paper and pencil. I have a clipboard with a tracking sheet created in excel with rows for each thing that needs tracking and columns for the day. Then I don't have to think, I just fill in boxes, and the pencil and paper are always right there on the wall in the bathroom, where the data is "generated" :)

This also lets me scan quickly across for daily and weekly trends. I have room at the bottom for longer notes if necessary. I put a [1] in the box and then a note that matches.