Never miss twice.

You procrastinated for one day? That's fine, life has its ups and downs, it happens, BUT ---- don't let it turn into a week. Do NOT think "I let it happen yesterday, so it's fine to let it happen today either".

Do NOT let one slip up spiral out of control.

More important than a machine perfect discipline, is refusing to let your bad days outweigh your good ones. You couldn't do it on a bad day? FINE! But do it now! it's a decent day! you have time today!!