@Kez0777 here's my list of things to do - all unashamedly stolen off the internet 
Working Out - marshmallows on either end of a straw
Swinging from a toilet roll with string
Find the hidden treat (underneath paper cups)
Snow Angels (with sprinkles)
Red noses or googley eyes on all all our photos (and them) - red pompoms
Arms through a slice of toast "it's so cold outside but we're toasty in here"
Head & shoulders inside a bag of sweets with sweets all around
Chocolate snowmen/santa - chop heads off and put elves inside
Move the spoons & forks and put elves in their place
Rolling down stairs inside a toilet roll (with arms up over their heads)
Replace toilet roll on holder with duct tape and write on it "this could get sticky!" hang elves beside it
Empty pringles tin - cut out space for arms & face and put elf inside
Wearing their masks holding a tape measure and a sign saying "stay 2m away!"
Lots of scrunched up paper balls and the eleves having a snowball fight!
Elves all tangled in dental floss and a note saying "we were trying to do the floss!"
2 candycanes to make a heart shape and a note saying "we love you"
Golfing - cut out small green shape, use candycanes for clubs and mini marshmallows for golf balls
Doing their elf-ercises
Climbing up the walls - attached to gift wrap bows
Sitting on sofa with small bowl of popcorn and remote control between them
Mess with cheerios and spell out "it wasn't us"
Elves in a big bowl of skittles or smarties with a "ball pit" sign
Toilet wrapped in toilet paper and elves with paper & sellotape stuck to them
Inside paper planes stuck in the christmas tree
Playing tic-tac-toe - the grid drawn on a sheet of paper and the Xs and Os drawn on top of mini marshmallows