It's easy to get stuck in between tasks, trying to determine what is the best thing to do next. This leads to an excess of planning and strategizing, and not enough doing. I had two anti-procrastination thoughts today about the Doing phase of the Getting Things Done methodology.
1. You don't get better at making decisions by thinking or planning, only by doing. It sounds counter-intuitive, but sometimes you can't tell what the best choice is in advance. Only when you choose something and actually do it, can you see the results and use them as feedback to make better choices later.
2. If you're stalled because you don't want to choose "wrong", think about this: if it's in your system as an action item, it's not wrong. You've already processed the item and decided what it means for you, what the next action is, and put that action on your calendar or an action list. So if you can't decide what to pick, pick anything at all, rather than continuing to stew. Anything on your list will move some priority forward, and will provide feedback on what to choose next. Plus, once you're in motion, it's easier to stay in motion and pick the next action... and the next one after that.