The wedding reception is the first time the newly married couple truly socializes with one another as bride and groom. It's the first time to share time with friends and family members as a married couple. It's also the time right before the honeymoon starts, and many newlyweds are getting pretty nervous as the reception comes along--even more nervous than during the wedding. To break the ice, try some fun wedding reception surprises.
Give everybody in the wedding party masks to wear that feature celebrity faces. When the bride and groom walk into the reception, they will find themselves looking at an A-list celebrity party. This can create huge laughs, especially if Mom and Dad are wearing the most outrageous of the masks. You can even theme it based on groups of families and friends. One part of the family may be the Brady Bunch, and the other part may be the Osbournes. Have fun with it.
Give mock speeches for the first few tries. (This should later be rectified by a proper speech). It should usually be done by the bride's family, but it would be funniest if done by the most conservative-behaving of the families. A father acting drunk while roasting his son-in-law is a good prank, but make sure that the bride and groom have a comfortable, easy relationship that makes this funny instead of inciting a fight on the most important day of their lives. This part is hard to balance successfully. When in doubt, do without. Keep it lighthearted.
Have the DJ work with you in pretending like he only has a certain type of music. Pretend like you accidentally booked a band who can only play polka music. When the couple starts to actually get frustrated, have the real band step up and play the couple's favorite song.
Make up last-minute excuses directly after a wedding ceremony for not attending the reception. While all people attending should accept the invitation to both the wedding and the reception, have a large amount of people back out at the last minute. In addition to the people backing out, all should hide at the venue. Then have all hide in an adjacent room, with one person keeping an eye out. Have the bride and groom show up to find nobody at their reception, despite many people at their wedding. Pop out to surprise them when the joke stops being funny.
Write outrageous things on the car for the couple to find on the way to the reception. While decorating the car of the bride and groom is hardly an original concept, this can get really funny if you go the outrageous mile with it.
Dress it up. The bride and groom have the most important costumes of all. Do a theme like "Two Worlds Collide." In this, half the celebrants can dress up like exaggerated types of people on Earth--from trashy to trendy--and the other half can dress up as aliens in all their fictional incarnations.
Hire a celebrity impersonator that is the bride's favorite singer. Have one that is the groom's. Let the two duet together all night for an ideal, fun pairing of the favorites of the couple coming together as one.
Always plan your fun ahead of time and be sure to include everyone who needs to be included in the joke.
Don't do anything that might offend the bride or groom. It's not worth a laugh at their expense. Keep it in good taste an in sync with their senses of humor.