Balloons? Paint? Running through a field? How to approach engagement photos...

Next week Mr. T and I will be doing the engagement photog thing. I'm excited and nervous. We've never sat for portraits together. Indeed, it's been a decade since I had my own portrait professionally taken (the Olan Mills church directory debacle not-withstanding). How does one prepare? I assume I will break out the night before and I'm praying my fab photographer Beth can clear things up via Photoshop. But what to wear? I've seen the gamut online--everyday jeans to ball gowns, etc. What makes sense? Look like me in my regular jeans and t-shirt? Or gussy it up a bit?

And what about props/themes? I have to laugh at the wedding blogs online. There are: diner shoots, and trailer park shoots, vintage hats, fishnets and umbrellas, and couples painting each other. I admire the creativity but wonder--are those real couples? How do they keep from giggling hysterically in those get-ups, and/or being palpably awkward and uncomfortable?

As this post is my "break" from homework, I'm decidedly over-thinking this and so I digress... Do you have any advice? Anything you would have done differently if given the chance? Any must-have shots? Do tell!