Gamasutra has a short article discussing how to avoid getting too enthusiastic towards a project and remain
focussed on the final goal. Here's a clip:
We need to rein ourselves in. We could tell everyone on the team that they suck and their ideas are valueless, but that may be going too far in the other direction. Here are a few good ways to apply reins without turning the entire team into a bunch of listless zombies who just phone it in."
Click here for the full article. Note that you need to be a registered member of Gamasutra to access it.