Of course, you invite your close friends and family. Have a great buffet with all kinds of fun foods. Check out one of my fav sites for ideas:
Also, have your Best Man & Maid of Honor do a funny toast (share a funny story - something embarrassing or silly would be nice - not something formal for a wedding).
Have a dance contest and the winner could receive a movie gift certificate and do play musical chairs with a similar useful gift.
Open your gifts together and have your bridal party make hats with paper plates using the bows and paper for bride, groom and bridal party (bring tape, scissors and cheap ribbon, stapler).
As a thank you, have small cards printed up with poem on card stock from staple's or other printing store -
Jack and Jill went up the hill to fetch a pail of water
Jack fell down and broke his crown
And Jill came tumbling after.
Up got Jack, and home did trot
As fast as he could caper
He went to bed and bound his head
With vinegar and brown paper.
And attach with ribbon to a boy & girl figurine - you may be able to get something similar at a 99 cents or other discount store - seehttp://www.amazon.com/Ceramic-Figurine-Blonde-Girl-Kissing/dp/B002CS24V6
Have your guests bring something for the "Wishing Well" like a can of beans, or soup or tea, or coffee or any small household product (like tissues or toilet paper) and place in a big bin. This is fun taking out these items and you can thank the folks who brought them to help furnish your home with these trifle, but needed items.
If you need invites, and thank you cards printed, I'd be happy to offer you a great design for around $60.
Let me know.