Well, you can get boxes that will set inside each other with peanuts (melt-able ones easiest for your clean up) make sure you use duct tape around each box that is filled with a smaller box, peanuts, crumpled news paper, each one having been wrapped. The one my bro did was up to a dishwasher box! And in the smallest box their was a key (at that time, he had rebuilt a jeep for my dad). Now this is when you could place a nice box, like jewelry type with a stick of gum, chicken pearl or a mint according to how badly you want to get him back. (Personally I'd do the stick of gum! LOL
A few years later, my bro (again) had brought some raw rubber home with him from the tire shop he worked at, wrapped a pin that was in its box, I wanted that pin so badly, then he baked the rubber...heat makes it set and its like peeling a tire on the car apart.
That was after the Christmas prior to I had picked him up different batteries, some expensive that he wanted...and each box I wrapped in plastic then with paper mache the box was nicely wrapped.
We have such a small family that its just fun to prank each other, not maliciously, a great uncles teasing is one thing, but to bring tears, there are enough of those in this world! Have fun and good luck!