I test a lot, up to 10 times a day, so I test my right hand on Sunday, Tuesday, Thursday, and Saturday, my left hand on Monday, Wednesday, Friday. I test the sides of my finger tips, beginning with the pinky finger, once on each side, then continue with the other fingers as needed. This helps me avoid sore finger tip pads.
It's easy to remember. I test only my right hand on weekends.
Always remember to wash and dry your hands, or finger tip with soap and water prior to testing. If you get a high (or low) reading, you can wash your finger tip again then re-test.
Happy testing!