Thinking back to the time leading up to my getting sober, and actually doing the stuff to get sober and stay sober, I must say that, although I did many of the things on the lists above to ensure I wouldn't relapse, it seems that relinquishing my ambivalence (about ever drinking again), and making that one phone call to an IOP program are the defining moments for me.
Resolving in our minds the 'to drink or not to drink' question (and maybe this comes after the act of seeking help for some) and then making a step and asking for or seeking help (in any form) seems to be a necessary part of it.