DPI:
What media effects have made you cringe as an audience member?
like fog on stage. Can be good but is dangerously cheesy.
Hal Eagar [1]:
Projecting a picture of the "set", I admit It still sometimes happens in my designs, and actually the "All Wear Bowlers [2]" example I list as a favorite was exactly that, so it's not that it's 100% bad, but it's defiantly a dangerous choice.
Another thing to watch out for is "one big screen", it's not necessarily bad, but it's got a lot of danger to it. There is a high chance of it either being dull, or drawing too much audience focus; or worse both. I like multiple screens, or heck no screens at all, just free floating media.
Links:
[1] http://www.digitalperformance.org/users/hal
[2] http://www.four3.com/allwearbowlers/