Classic cling film trick! We get upto quite alot to be honest. Squaddie banter level is high, il have dig out some pictures heres one though.
Out in Afghan we have cut / shave our own hair so we did one of the boys like this and hid the shavers after!

!Removed! brilliant mate

Knew it wouldn't be long till someone put some sort of !Removed! up.
One of the best things I did was shrink wrap a poor bloke to a chair then we just rolled him into a storeroom and just left him there.
Some git actually played a little trick on me today, nothing major, they just chained my bag to a chair so I was just like riight

when I went to pick it up. Knew it would be one of em so I just chained everyone's bags together to a chair then pee'd off home