I just use a small piece of paper, jot down the needle size and date changed. Tape it to the far right bottom section of the machine, or somewhere on the machine out of the way from fabric movement. When I change again or use a different size needle for whatever purpose, I add to that note or get a new scrap of paper. Can tell at a glance when I last changed needle whenever anything out of the normal occurs......breakage, jams, etc. I do use a piece of painters tape or washi tape to attach the note. Regular scotch tape is sometimes difficult to remove.