Tip #1: Screw the heels.  
If you don't end up twisting your own ankle, one stomp from that sassy stiletto will break your partner's toe (and yes, you will step on his feet... it's inevitable).  However "cute" your legs may look in heels, you need flats if you are going swing dancing- without a doubt.
Tip #2: No strapless bras!  
Wearing a strapless bra is asking for that uncomfortable situation when you don't realize that your bra has slid down your rib cage and is now at your belly button.  Everyone, except for you, notices this.  Yes, that includes your partner.  Forget the worry, and remember the straps.
Tip #3: Want to wear a fun and flirty dress or skirt?  Go for it!  BUT DON'T FORGET SHORTS!  
Did you hear that?  In case you didn't know, swing dancing oftentimes involves a lot of spins and flips.  The last thing you want is to find yourself upside down, with your skirt over your head, and your panties making a big debut.
Tip #4: Put those low-rise, hip huggers back.  No want wants to see a plumbers' crack.  
Hey, that rhymes!  Remember that one.  If you're going dancing, you want to be able to have a decent range of motion without making the people around you cringe.
Tip #5: Keep jewelry simple.  
You don't want any long, bohemian necklaces or sharp cuff bracelets getting in the way.  The next thing you know, you will have strangled yourself with your necklace or ripped his shirt.
Tip #6: Silk and satin are asking for a "slip-up".  
Wear a fabric that has some friction, like cotton or a poly-blend, to avoid slipping right through his hands.  Cracking your head open just might put a damper on the night.