Bruce MacEwen has a nice piece on leadership that takes off from the recent HBR article about Havard's Program for Leadership Development. Vision, Decision (And Reservations).
What I keyed on what something he wrote near the end of the article around making decisions. Not only do you need to articulate what to do and why, but you also need to articulate the reservations you have about the particular course of action. What does that give you?
The reservations enlist genuine support, changing "We're going to do this so shut up and get on-board," to "We're going to do this so long as...." It makes your decisiveness and your vision realistic, in other words.
And, surprise, admitting things might not be perfect enlists support. You're not omniscient, and claims to the contrary alienate rather than attract. Decision; vision; reservations; speaking each individual's language. Leadership.
I've been learning in my consulting practice that when I come across as "having the answer" I never get as far as I do when I offer a suggestion (that I think will work), and ask my clients why it won't work. There are a variety of questions I could ask along these lines, but they all center around surfacing obstacles and unintended consequences of the idea. And, conveniently, when I bring other people into the conversation, I usually get a better solution in the end. Just as Bruce says above.
With your next brilliant plan ask yourself, and your colleagues.  Why won't this idea work?