Try to fake it with an embroidered eye-catching hat. Personalized designs are available in this great store http://www.zazzle.com/bachelorette+embroidered+hats You can use naughty bachelorette-type quotes to tickle people's imagination and steal focus from the less than perfect hair.
Movies say "flip your hair", but really you make want to use a pick and some detangling spray and get out the tangles. Then you can either brush your hair or use a flat iron to make your hair flat (or both). Hope this was what you were looking for!!!!
Clips are amazing for bad hair days. Pull your hair back as if you were going to make a pony tail, and twist your hair in a figure 8 on top of your head. Secure it with a clip, and you're out the door!
A hat. Of any sort, really. But if you are feeling whimsical, there's lots of shops that sell the most adorable quirky toppers! You can get them with whirly gigs that spin around, ones that light up, even ones that have "I'm having a bad hair day" written on them. Some even come with fake tresses and locks, to make it look like your hair is fine.
A paper bag, however, works nicely too.
I sort of dig having a bad hair day. It wigs people out when I traipse about in public, not caring that they are staring. Get it? "Wig" Out? Oh, my. Someone thinks they're funny!
Don't do hats. There corny. For me I would either braid it to the side. Make a nice part on the side of my head and braid it. Also it's really common for girl to do this and it works. Take a peace of your hair on the side (front) and just twist it back. Then bobby pin it down. Or you can do a fish tail to the side. Or tie your hair in a ponytails