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:

Projecting a picture of the "set", I admit It still sometimes happens in my designs, and actually the "All Wear Bowlers" 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.