Not only do I plan events, but I attend a large number of events. Here are three things that make me crazy:
1. Centerpieces that block the view of half the table: What's the point of being seated with 8 or 10 people if you can't even see half of them because of the centerpiece, much less be able to engage them through the centerpiece? There are plenty of nice ways to decorate a table that won't block the view of others at the table.
2. Those stretchy chair covers that totally cover the chair legs: Remember when our legs didn't bounce off the chair covers at events? Whoever created those stretchy covers has turned already uncomfortable event chairs into ones that require you to stretch your legs out in front of you at a table. And forget about being able to put anything under the chair. While I know it makes the space look nicer to have covered chairs ... UGH!
3. The band that plays loudly during dinner: I was recently at an event where I spent the dinner either screaming at the person directly next to me so he could hear me or we both were saying over and over, "what did you say, what did you say" ... Whatever happened to nice, quiet background music at banquets that accommodates conversations?
Events should strive to encourage conversation at the banquet tables; and be as comfortable as possible.