I find that action builds momentum. The best kind of action is decisive action because then you are "all in." Dipping a toe in the water doesn’t make the same splash as diving into the pool.
When I'm under the gun, "satisficing" to make decisions serves me well. Gary Klein wrote a great book on how experts make rapid decisions under fire. (The book is Sources of Power.)
Some of the techniques I use include: criteria and weights, CARVER (Criticality, Accessibility, Return, Vulnerability, Effect, and Recognizability), and Six Thinking Hats. At Microsoft, I tend to use criteria and weight when I need to get agreement with others on what the priorities are. I also tend to use Six Thinking Hats when I need to rapidly have folks change perspective, and take a more holistic view. To make the most of Six Thinking Hats, I use questions at the whiteboard to focus the thinking and work our way through the hats.
At the end of the day, I've found that a lot of the decisions come down to who do you want to be and what experiences do you want to create. Basically, the more you can connect your decisions to your "Why" or to your values, the stickier they are.
In fact, the secret of changing habits is to first decide who you want to be and our identify helps us pattern match the best fits.