Mine was lots of years ago now, but we did a fun activity (white water rafting) in the morning, followed by lunch, a sex toys/lingerie party, dinner, and a trip to the pub where I had to do various challenges. Although it was a really long day, it meant that my friends (many of whom were shifts workers) could come to at least some of it if they couldn't make the whole day. We kept the cost down by catering for the lunch at a friend's house. There was no theme although I was dressed as a bee for some bizarre reason (I got no say in that )