The post it prank may be a classic prank but that doesn't mean it's not a good one! The key to this prank is being thorough in your execution. Start with a game plan and make sure you buy enough posts its. Do some quick measurement and then calculate the rough square footage you need to cover. It takes 16 post its to cover 1 square foot. The key to a legendary prank is taking it that extra step, leave no white space and you'll get the best results. For cubes with fabric walls use a stapler to secure the post its so they don't fall off. Varying your color scheme also goes a long way to making this prank more impressive. Note our use of blue for computer items and whiteboard while we tiled the walls in yellow. The overall look will appear far more complete with a little bit of planning.
Random tip: don't buy accordion-style post-its, they slow down efficiency of post-it-ing.
Prank Stats:
Cost: <$40
Time: 1 1/2 hours w/ 3-5 people
Difficulty: 3 out of 5 (medium)

This is one of the easiest and cheapest pranks out there. While a co-worker is away do some "renovations" to their cube. To achieve the result here we simply used black trash bags which we duct taped together along the way. To add another level to this we cleared off her entire cube and hid all the items within different drawers and cabinets within her cube. Oddly enough people rarely look in their own desks first so there should be a few moments of hilarious confusion after they remove all the plastic. 
We like to keep them guessing.
You thought you may have figured us out
We're sure you saw the stapler in Jello on The Office, when Jim did this to Dwight so we thought we'd show you how easy it is to do. This is a fun and easy prank that requires no special occasion other than needed a good laugh. Especially great if a co-worker is really attached to their stapler. Those with red swingline staplers are excellent targets for this one. 

success for these kinds of pranks are 80% thoroughness/attention to detail. And these pranksters never settle for 2nd best.