I think first of all you need to develop a sense of when something requires decision, and something requires marinating.
Anne Bogart talks about it wonderfully in her book “A Director Prepares” when she talks about two concepts in aikido: irimi and ura. Ura is to circle around, while irimi is to “to enter/to choose death.” In a combat situation, sometimes it is better to go around, and sometimes it is better to confront it directly.
I recognise sometimes I am holding off a decision because I am afraid of committing to something. I’m afraid of making the wrong decision and looking stupid, when I actually know (deep down) that what I need to do is to take the plunge— more time and thought is not actually going to help.
In this case it is about being honest with my fear, and then just going for it.
Verbally, I notice that I have a tendency to meander when I am not certain or confident about a subject. In fact, the more uncertain I am, the more academic and convoluted my writing becomes. When I catch myself doing that, I laugh at myself. “hello, here I am again, writing b.s.”
As for training yourself to respond quickly, I would try exercises where you have to respond quickly. I know you like theatre, so go and do theatre improv or something. In terms of writing, do some free-writing (“Writing down the Bones” by Natalie Goldberg is a wonderful book, I think it was very influential in helping me figure out and develop a habit of creative discipline). If you like to move, go do some dance improv, contact improv—things where you have to respond to the moment in a loose, relaxed manner.
I promised myself that I would produce a blog entry a week, and by giving myself a deadline, I have to produce something readable. Give yourself structures which you can push against.
=)