It's just common sense, but I think it bears repeating: Take some time to scan your meeting space for its effects on all five senses. For some great advice on how to conduct an environmental scan, check out this post from The Forum Effect. I particularly found this tip useful:
This is an additional element that is not one of the five senses, but crucial nonetheless. Take a moment to observe both worker and participant behavior. Make sure staff are keeping private discussions out of earshot. Watch participants to see if they’re encountering problems. Perhaps they can’t find the restrooms or have lost their pen. By observing behavior, you’ll be able to quickly and effectively keep participants focused on the reason they’re there: the meeting.