I'm totally skipping the shower since I live far from family and friends but if I was to have one it would be casual and just a joining of family and friends, with no presents and lots of delicious food (and cake, everyone loves cake).
It gives wedding guests and friends a chance to get to know each other before the big day, and is a celebration based on all the right reasons.
I've definitely shelled out a lot of money on bridal gifts before, then felt frustrated at the end of everything on how much it was for their shower gift, bachelorette costs, wedding presents, presentations, etc. It really adds up :S