Self-herding is when you refer to your past actions for subconscious guidance rather than mirroring what others around you are doing. This effect can persist a lot longer than the situation that produced the action. By taking advantage of self-herding, we can use temporary circumstances to shape persistent, long-term behavior. 

A common method for doing this used by successful SOF candidates is to "quit tomorrow." 

No matter how much what you're doing right now hurts, you can tell yourself that you'll finish out today and quit tomorrow. This takes away the daunting prospect of future suffering while focusing you on pushing through today's challenge. 

Most of the time, people do this in reverse. They take the easy way out today and tell themselves that they'll do the hard thing tomorrow. But tomorrow never comes. Each day they make a new excuse, skip the hard work, and put the burden of their ambitions onto their future selves. Present-day actions never match future goals. 

Quitting tomorrow helps you do the hard work today, by mentally promising yourself that you can take a break tomorrow. In the same way, tomorrow never comes. Each new day becomes just one more today in a long string of them in which you suffer through one last time. 

Just as making an excuse and avoiding discomfort becomes a reflex for many people, quitting tomorrow makes a habit of perseverance.