Start a chain-link and add a link to it everyday you don’t self-harm, hang it up if possible
to make this you need scissors, paper (colorful is best), and glue/tape

to make a chain link you cut a strip of paper and tape/glue the ends together

in order to attach them together close it around the previous one

an interesting way to do it is to have 2 colors of paper, for each day you have an urge but do not self harm put up one color and for every day you don’t even have an urge put up the other color, I find this was more inspiring, because you can see a differences as time progresses