whatever floats your boat...
After 3 months, I generally take apart an idea over the course of days. I'll destroy it from every angle, and I'll show from as-simple-as-possible logic. Every single sentence has to be sound logic, and every tiny nook and crany needs to be explored.
The first three months are for my emotions to settle and solidify. The next 1-2 weeks are for me to have a logical, impartial, and objective argument with the idea. A portion of it is to assume the role of a 12 year old internet troll and absolutely assault the idea from every angle. There cannot remain even a single facet I am unsure of, or uncertain of, or cannot backup with facts or logic stemming from facts.
If it stands after this, then it becomes second nature to begin. There isn't any giddy enthusiasm, but there also isn't any hopeless depression when encountering an unknown. The fight has been fought, all that remains is execution. Starting is weary, and execution is tame. There is no gut-sinking defeated feeling once the euphoria wears off: there's just a logical argument - written down - for what needs to be done, and why.
This is how I've made some of the most difficult decisions in my life, and it has so far worked. It protracts the decision making process into months, and that's inefficient and sad. But it is guaranteed to work for me. This is how I have lost a very significant amount of weight, and how I have stopped smoking.
A part of it is, for me at least, to acknowledge that I dislike change intensly. I don't think I'm unique in that regard among humans, but it's something I feel passionate about changing. If baby steps is what's required, then baby steps it'll be.
My next goal is to begin running. I'm in the first month of the fermentation stage: the passion to start running 3 times a week has been building within me over the last 3-6 months, but I've gotten serious about it last month. Now the 3 month waiting period begins. During those 3 months, I'll begin kicking things around my head. Just this morning, it occurred to me that I'll need to keep a precise schedule, and if I lax from it, then I'll miss a day, and this makes me very worried. I want to be disciplined about it. I'm not sure how I'll solve that - perhaps run in the afternoon? It's something I'm going to work out by the end of January.