An excerpt from Rework (by Jason Fried & David Heinemeier Hansson)
Big decisions are hard to make and hard to change. And once you make one the tendency is to continue believing you make the right decision, even if you didn't. You stop being objective.
Once ego and pride are on the line, you can't change your mind without looking bad. The desire to save face trumps the desire to make the right call. And then there's inertia too: The more stream you put into going into one direction, the harder it is to change course.
Instead, make choices that are small enough that they're effectively temporarily. When you make tiny decisions mean you can afford to change. There's no big penalty if you mess up. You just fix it.
Making tiny decisions doesn't mean you can't make big plans or think big ideas. It just means you believe the best way to achieve those big things is one tiny decision at a time.