Everyone always emphasizes the importance of details. However, 37signals' Jason Fried notes, sometimes, details can keep you from getting actual work done.
Fried writes about how our obsession with the importance of details sometimes fails to acknowledge their relation to timing. Getting caught up in details too early can kill your enthusiasm and halt your progress if you aren't careful:
Don't worry about the size of your headline font in week one. You don't need to nail that perfect shade of green in week two. You don't need to move that "submit" button three pixels to the right in week three. Just get the stuff on the page for now. Then use it. Make sure it works. Later on you can adjust and perfect it.
It may seem like Fried is ascribing to the "done is better than perfect" school of thought, but he isn't, necessarily. There is time to perfect things, but doing so from the start can set you back considerably, so make sure you save them for that last 10%.
Ignore details early on | 37signals