1. juiced a lemon and now left with an empty shell? then clean! sprinkle some baking soda on a greasy nasty mess and rub it with the lemon half. smells great and non-toxic! you can also add salt as an extra abrasive! (just be careful on delicate surfaces!)
2. compost! contrary to popular belief, YOU CAN ADD CITRUS PEELS TO YOUR COMPOST! i don't know who started the myth that you couldn't, but many a gardening site says that doing so is JUST FINE. you just don't want an entire compost pile made up of mostly citrus.
3. does your garbage disposal smell like old feet and rot? throw in a few citrus peels and turn it on!
4. i haven't tried this, but a friend of mine swears that if you take a dingy glass coffee pot and throw in some salt, ice, and leftover lemon peels and mix it up for a bit, your coffee pot will look sparkling clean when you rinse it!
5. aromatics! simmer some lemon peels in water! mmm lemony fresh! want a stronger smell? simmer orange peels and cinnamon sticks (and cloves if you got em!) in water, and your house will smell AMAZING. this will also clean out any old gunky stains you may have in your pot while you simmer!
6. dry for potpourri! ugh... somehow, every time i try to type potpourri, i type poopourri... anyway!
7. rub a juiced lemon shell on a cutting board to freshen it up! it also removes stains and sanitizes!
8. one cup of leftover citrus peels + 750ml of vodka in a jar = awesome. (you want it to sit in a cool, dark place for a week to make sure to really get the flavor in there!) for a sweeter recipe, try THIS.
9. cleaning spray! put leftover lime, lemon, or orange peels in a jar and cover them with three cups of white vinegar. let this mixture sit for about two weeks in a dark place. dilute the mixture when you are ready to use in a clean spray bottle. spray and clean! (you really only need about one cup of the peel mixture per spray bottle when you go to dilute it!)
11. clean that funky cheese grater... take your left over juiced lemon and rub it on your grater.. all the gunked up stuff should come right off and it should rinse nicely.
12. zest and DRY (spread out on a clean paper towel and to let it dry out)! you can freeze it for later use or add zest to pepper or salt for an amazing seasoning!
13. orange sugar scrub! there is an amazing recipe HERE. check it out. your skin will love you.
14. make candied orange peels! i don't have a favorite recipe for this, but THIS ONE is pretty nice. you can also dip the finished "candy" in dark chocolate for an extra yummy kick!