Everyone is different
Incentives that help your teen battle procrastination may very well be different. Sit down with them and have a chat about what little things would motivate them.
They will often have a few ideas that you wouldnt have thought of that might work very well for them.
Using incentives it just one example of all the really simple things your teen can do to help transform their grades.
Maybe using incentives will be your teens magic bullet for study success?