If you can't decide about something, it means you lack enough information to feel comfortable making some choice. Therefore, the next-action coaching question would be, "So what action do you need to take to begin to get the information you need to make that decision?" Nine times out of ten, there's a specific action to take, such as "surf web re: xyz" or "e-mail A & B to set meeting to explore options about xyz."
Every once in a while, though, the information you need has to come from inside—i.e. your intuition. You need to sleep on it. But even then, to really clear your head, you need to make the decision about how long you can "just sleep on it" until you feel like you need to actually make the Big Decision. Two weeks? Two months? Four days? Six hours? Whatever that answer is, you simply need to park a trigger in a calendar or tickler file to yank your chain at that point, ensuring that you re-assess the situation in your own timing.
Sometimes it's not a lack of information, but motivation. And strategies exist for that lack as well. There is hope.