My kids and I do our best to play practical jokes on each other...crimbo and birthdays being the ideal opportunity. It's rubbed off as they've played a few fun trick on grandparents...
With my MiL over the past few years they have overwrapped her gift
(top layer of wrapping paper, loads of old news paper, even cling film and tinfoil) so it it took her about 20 minutes to open her gift. They've also packed a small gift into a large box filled with the contents of our shredder so she had to root about for it
(they had also hidden a rubber snake in the shredded paper)
The funniest
(and most subtle) one was a couple of years back. My FiL was handed his present by my kids and I noticed they stuck their fingers in their ears and winced slightly. I've never seen a present opened so carefully although there was nothing untoward in it, they'd just agreed ahead of time to mess with his head
.
A couple of times I've arranged little challenges for my kids on xmas, especially when my wife has been working
(she's a nurse). One year, it was a treasure hunt to find clues to tell them where to find their presents. They enjoyed it so much that the following year that the majority of the clues were hidden in local woods and fields and took a couple of hours to solve...they had already been given their main presents and the 'treasure hunt' was just for one of their smaller gifts/