A masquerade ball is all about the costumes (or at least the masks), so make sure they're the focus of attention for the gathering. It's a good idea to have someone strategically placed to take photos of guests as they arrive as well as candid shots of them throughout the evening. These tips will help too:
Choose a theme -- Settle on a color scheme as well as two or three decorative elements you plan on repeating throughout the space. Repeated colors and other elements will make the room look more organized and cohesive.
Use masks in your decor -- Exploit the mask idea by using colorful masks in your decor. This can be an inspired solution to a couple of problems. It's easy to come up with really beautiful masks using supplies available at your local craft store, and masks are pretty inexpensive to put together, too. Hang them from the ceiling with ribbon, dress up balloons with them, mount them to the walls (or over mirrors), use them in your table centerpieces or add them to decorative wreaths. Here's an extra added bonus: If a guest arrives without a mask, loan him one of yours.
Avoid overcrowding -- A pirate trying to swagger around wearing a big hat on his head and a patch over one eye probably isn't watching out for your Aunt Edna's crystal candy dish, so give him plenty of room.
Play the right music -- The harpsichord may not be your favorite musical instrument, but if you're having a period ball, using authentic music will help you create the right mood. There are lots of musical collections available to help you recreate the sounds of a specific decade or musical style. You may also be able to find a period film with a great score that brings, say, the roaring '20s to life for your guests.
Pay attention to the lighting -- A masquerade party is all about creating an illusion. Don't let bright lights and glaring white walls spoil the fun. Choose soft lighting or even colored lights. Christmas lights strung along banisters and on a patio or deck are a good idea, too. Where lighting is concerned, keep things romantically muted.
Provide a place to change -- Some guests may prefer changing into costume after they arrive. Make it easy for them by providing a quiet place to get into character. It's also a good idea to have some emergency extras around like safety pins and a sewing kit.
Pick a punch -- Whether you're serving alcoholic beverages or not, having a specialty punch prepared for the occasion is always nice. Serve it in a glass or crystal punch bowl for a festive touch that will make your table look special -- particularly if the color of the punch reflects your decorating theme.
Keep the menu simple -- Like a cocktail party, the appeal of a masquerade party is in getting people to mingle. If you're serving refreshments, keep it simple, though. That way, there'll be fewer pasta sauce mishaps.