Dress - if you're over 20, you should have lost any infatuation with fads. Conservative suits and dress clothes, jeans and flannels. It's great for the ERE lifestyle because you can wear the same clothes for twenty years and no one blinks an eye.
Speech - Not a lot of modern slang. I'd refrain from swearing and discussions of abstract concepts until you're sure of your audience.
Possible ERE City -- Lincoln, Nebraska
@Jacob - Not at all. There are plenty of educated people around here. They just like to get to know you, where you're from, etc. before getting into the meatier stuff. I think too many people were raised in small towns where using big word comes across as "pompous and faggy". Also where pretty girls don't cuss.