by Kim Grundy via USA Today Halloween is all about creative costumes, hay rides, fun parties, haunted houses…and the candy. So much candy. Don’t toss leftover Halloween candy in the trash, however – not when there are so many smart uses for all of those Snickers, Twix bars, M&Ms and Skittles. In fact, you might even pick up a little extra this year (or hit that extra row of houses while trick-or-treating) and have fun testing out these tasty ideas from Thanksgiving.com , Grateful.co and the USA TODAY Network. 1. Donate your leftover Halloween candy What’s always a great option when you have more of something than you need? Give it away! Operation Gratitude sends sweets to deployed troops and first responders. Soldiers’ Angels Treats for Troops ships donates candy to veterans and deployed service members. Some dental offices and other businesses hold Halloween candy buybacks, in which they trade toothbrushes, floss or other ...