Whenever you feel the urge or need to cut you wait 15 minutes. During that 15 minutes you distract yourself and try to feel better by doing pretty much anything you enjoy.
EXAMPLES: reading a book, taking a shower/bath, playing games, hanging out with friends, talking to a friend that knows about your SI, yard work, etc.
If you still need to cut then wait another 15 minutes. If after that you decide you can't wait anymore then you can cut.
This works for me usually. I believe this can be a good habit because it can help you develop some control over cutting which is always good if you really want to quit