My first post on SXSW is from a talk called "11 Tips to Managing a Creative Environment." The speakers compiled the list after interviewing people who a) work in a creative environment, b) had to work as part of a team and c) had hard deadlines to meet. Some of these groups included entertainers (comedy troupes, theater groups, symphonies), media (print and online magazines), writers groups, restaurants, and a few others. Much of it applied to simply working in a creative environment, regardless of whether or not you had any authority.
One of the points they made was about the steps of the creative process and making sure everyone's on the same page in terms of what step you're at. This is critical in a creative department, but also important with a CW-AD team.
There are two phases in any creative process: divergence and convergence. Divergence is the brainstorming part. Churning out as many ideas as you possibly can. It doesn't matter if they're good yet. This phase is all about quantity. And the key here is to not judge. Don't kill ANYTHING. Don't say why you can't do it, why the client won't buy it, how it won't fit the budget. We all know this is the golden rule of brainstorming, even though we sometimes forget.
An important step to making sure everyone's on the same page is that, when you're done with phase 1, make sure everyone knows you are. End the meeting, or say "Okay, now let's look at everything we've got." One of the comedy troupes marked the turning point with a smoke break. When they came back from the smoke break, everyone knew they were in phase 2.
Phase 2 is the convergence phase. This is when the ideas are culled down, refined, combined and, yes, killed. You have to edit here. Be ruthless. Only keep the great ideas.
Now, the point I want to emphasize is that in this second phase, the golden rule is you're not coming up with completely new directions. This is about getting to a single solution, not creating more potential solutions--if you did your job in phase 1, you should have plenty. We've all been in meetings where we're trying to brainstorm and someone is shooting ideas down. It's frustrating, and it's harmful to the process. But just as harmful is to be throwing out new ideas when you're in the convergence phase. This is the time to improve the ideas that you have. A constant stream of new ideas in this phase can lead to chaos and frustration.
In an agency, young teams often fall into the trap of spending all their time in the divergence phase, then try to converge an hour before they're supposed to present their work. I'd say it should be closer to 60/40, depending on your creative director. Most will like to see a few ideas. None want to see ALL of your ideas. Make sure you spend time fleshing your ideas out. Give them the time and refinement they deserve.