Remain vigilant. Do not let your guard down.
One of my biggest problems would be that I would allow my AV to catch me off guard. I would experience a trigger -- a thought, a sight, a smell, a sound -- that would send me down the rabbit hole, and within minutes I had convinced myself to run to the liquor store. This happened on many day ones, and on many occasions it happened several months into previous attempts at permanent sobriety.
Make your addiction your arch nemesis. When it comes to alcohol/drugs, that part of your brain cares only about getting a fix, consequences be damned. It can not be reasoned with, and it can strike at any moment without warning, even after lying dormant for a while. It must be recognized and shut down dead in its tracks. And to do this -- at least in my case -- requires a constant state of 1)Accepting how vulnerable I was and how fragile my sobriety is, and, 2)Determining that I would not allow my addiction to capitalize on that fact ever again.
This is the foundation of my sobriety arsenal. Hope this helps.