Here are a few projects to do when you have a spare 15 minutes:
Free up space on your devices: When you are waiting on an appointment, start going through your photos and deleting the duplicates.
Find new recipes: While you have your household favorite meals, research and get motivated to try new recipes.
Set a timer and find the junk: Grab a trash bag and power through your house and car and get rid of the junk mail, wrappers, Amazon boxes, etc. (Tip: Only look for the trash during those 15 minutes, come back to the other projects later).