Here's how to make easy and fun sexy costumes. What's sexy varies so much from person to person that the possibilities are endless. Sexy costumes often focus on a theme, usually bordering on the fetishistic. Often, something normally considered innocent or good, like the role of nurse or librarian, can be made into something erotic and bad (in a good way). Of course, it usually takes a few naughty details to make the leap from good girl to bad girl.
For example, the right costume can make the nurse look go from helpful to hot when you wear a super-short white mini "uniform," with the top unbuttoned enough to show ample cleavage. (A Wonderbra will do wonders in making this costume sexy, too.)
Likewise, the librarian can go from mousy to MILF-y when you pair a cardigan and buttoned-up blouse with a teeny-tiny mini, black stockings with the line up the back, and super-high heels. If you can pull off the look, finish with a cute pair of cat-eye glasses. A pen perched behind your ear and a book tucked under your arm would be good additions, but only if you can stash them somewhere at some point.
The hot devil look is always a hit, especially at Halloween. Of course, you have to look good in red to make this sexy costume work. A red dress will do the trick, but another option is a leotard and tights, especially if you have a flat stomach and great legs. Red stockings (especially fishnets) are a great addition. Smoky eyes and red lips are necessities. Of course, you'll need horns, and a satiny cape that doesn't cover too much is a nice finishing touch.
Another perennial winner is the schoolgirl look. This is an easy sexy costume to make. A plaid mini-skirt is essential. You can buy one (although you're not likely to find them easily at stores like Target or Kohl's right now), make one, or pick one up at a store that sells parochial school uniforms (unless this makes you feel a little squeamish). Wear a white button-down shirt, but, of course, unbutton it low, and have a lacy bra peeking out. A tight cardigan and opaque tights are good, or you can bare your legs; go with whichever option makes you feel sexier. Mary Janes are a perfect shoe choice. Top it off with pigtails, and you'll ignite many a schoolgirl fantasy.