I'm doing a photo scavenger hunt for my party, but it's not anything to do with instagram. Just "find the 13 thirteens" - groups of objects that are 13 in number, the word thirteen on a sign, the number, or just hatch marks made in blood by a deranged clown. 
I'd suggest making a master list sign (so you don't have to keep explaining it) with clues of what to take a pic of... like have a raven/crow somewhere in your party decor, and a clue could be:
"A group of these is called a murder... but let's hope there isn't one of these at the party!" or "Quote the ? 'Nevermore!'"
Or for a JoL:
"He's got the biggest grin in the place and he really lights up the room!'
For the tag, maybe something like HallowHunt or AllHallowsHunt?
I'd suggest making a master list sign (so you don't have to keep explaining it) with clues of what to take a pic of... like have a raven/crow somewhere in your party decor, and a clue could be:
"A group of these is called a murder... but let's hope there isn't one of these at the party!" or "Quote the ? 'Nevermore!'"
Or for a JoL:
"He's got the biggest grin in the place and he really lights up the room!'
For the tag, maybe something like HallowHunt or AllHallowsHunt?
