When you go to a wedding, dancing is inevitable. Sure, you may sit there and refuse to dance. Or, you may want to but you're too nervous. Slow dancing is the perfect time to hit the dance floor because it's so easy to do.
Ask someone to dance. There's no point in sitting there during a wedding and wishing you were dancing. Make sure to start with someone you feel comfortable with--even if it's a friend, cousin or your grandparent.
Stand about 6 inches apart. The man's arms should go around the woman's waist. Her hands should go around his neck. The man can also keep one hand on the small of her back and clasp her other hand away from their bodies.
Go for the traditional side to side move if you're not much of a dancer. Sway back and forth, slowly turning your partner around in a circle. There's not much to slow dancing, it's perfectly acceptable to basically stand there with little movement.
Take lessons if you don't feel comfortable slow dancing. There's no shame in learning a few moves before the wedding. You don't necessarily have to go the ballroom dancing route--but you can learn a few stand-by moves to help you keep things flowing on the dance floor.
Stay in tempo. No matter what the song is and what your moves are, just try to find the beat and move along with it. Meaning, if the song gets a little faster, you should move a little faster, too.
Spice things up and do the unexpected. Turn a traditional slow dance into something fun and memorable by suddenly changing things up in the middle.