We tend to get so obsessed with the how and the when of a New Year's resolution. The imperative of starting on January 1 or we have blown it (you haven't). And the almost obsessional levels of the how to get it done (not as critical as you think). The how can take over the whole process: exactly what to eat, in what exact qualities, in what exact combinations, and so on. The training plan of how many steps or reps in how many days. This stuff is all good, but it's surface-level. Knowing how many antioxidants are in a juiced carrot will not be enough to sustain motivation by the time winter rocks round. Knowing deep in your core why you resolved what you resolved, will.
A few good resolution-setting questions are:
Why do I want this? Understanding and defining your why is mission-critical. Eating more healthily because everything you read is telling you to will just not cut it long-term. Think of your why as your spiritual fuel. It's the power that drives the completion of your resolution. If your why is weak you are likely to fall off the wagon. When times get tough, as they inevitably will, a "just because" or an "everyone else is" will not pull you through. You need to be able to dig deep and know why why why you are doing it. What does it mean to YOU, to your life, to achieve this goal? What's the defining reason you want to commit to this thing?
What's my target? If you don't have the specifics dialled in, it's going to be very hard to hit it, and feel good about it. "Eat more healthily" and "make more money" are classics. Define what this actually means "I will eat a minimum of five servings of fruit/veg a day" or "I will add an additional $5000 income" will drive behaviour far more consistently and powerfully. Set the bar at a level that you can hit consistently, getting yeses on the board, and then you can stretch yourself and raise the bar higher as you continue and that habit is already established.
What is it going to feel like when you reach your goal? When you slip on that size 10? When you cross the finish line? When you play that duet? Again this is spiritual fuel, it's the foundation of a successful resolution.
It's where you tap into when things seem tough and why did you start this stupid resolution anyway? Reconnect with how it will feel when you get what you want. That "desired feeling" state is a powerful motivator for commitment to change long term. All the useful how-to information is at its most powerful when you layer it on top of that core commitment to why you want what you want, and how it will feel when you get there.