2) Make a post with the subject "trick or treat?". Put your "candy" somewhere in it, and be sure to repost these instructions.
3) Then, go around other people's LJs and reply to them with either "trick" or "treat". If you reply with "trick", they will give you an LJ dare that you have to perform before taking their candy. If you're too wimpy for that, simply say "treat" and take their candy.
4) List all your collected candies in your original "trick or treat?" post to show off your collection, being sure not to direct-link!
tsubame_17 had me find some Gaara/Sakura fanart!
ranty_rie had me post a 500 word entry in poke-language, using only my username! Entry here!
nikurumi had me change my journal's subtitle to I LOVE COOKIES ♥ for one hour. Start: 6:47pm. End: 8:19PM.
piernik_is_here had me end each comment/entry I made with I ATE PIKACHU.
annwyd had me write an entry speculating on what type of underwear various Princess Tutu characters wear. Entry here!
pommello had me type in pink for the rest of the night!
blueridicule hAd mE TyPe My cOmMeNtS lIkE tHiS UnTiL hAllOwEEn WaS OveR.
mizu_koetatsu had me post an entry containing a certain GIF six times. Entry here!
chopinston HAD ME POST ALL MY COMMENTS IN CAPSLOCK UNTIL TOMORROW.
strawberryrin had me have at least 5 emoticons in each comment for 24 hours! =D =D =D =) =P
sparkledyne had me put a horrifying picture in my userinfo until Halloween is done. This is the closest thing I have.
aleator had me comment in Yoda speak, she did.
breakfastgirl had me post an entry in part blue, part red, and part green. Entry here!
hirato had me post an entry with ten good reasons why I love Sasuke. Entry here!
veresade had me make an entry in Norwegian using the Google Translator. Entry here!
carshrimped had me make a SPAZZING AND FANGIRLY ENTRY ABOUT AN UNTHINKABLE OURAN PAIRING!!!11! Entry here!
I found this last December, wanted to do it, and completed forgot about it until someone on my flist did it. Which reminded me.