Place small water balloons in the toe your victims' shoes in such a manner so that it's not visible in the first glance. they'll get a chilling surprise! (more expensive the shoe, the more will be the fun but it should be avoided to prevent a ruckus)
add some yellow food coloring to water, and sprinkle it liberally all over the toilet seat and on the floor around the toilet.
Stuff victim's shoes with some cotton, when the person will try wearing it they will feel that either their feet have swollen or the shoe has shrank.
Try covering the urinal with a good quality cling film, tie it tightly so that its not visible at at a glance then wait to see who gets splashed first.
Take a slice of cream cheese or jelly and carefully insert it into the deodorant container after scooping about an inch of deodorant from the top of the victim's stick deodorant. sculpt cheese or jelly well so that it looks like a deodorant. put the top back on and wait for the fun!
Carefully open a small bag of chips by pulling apart the top, then remove the wafers. replace them with some other type of chip, or fake cardboard "chips." then glue the top back and offer them to your victim.
Place a stuffed mouse or small stuffed animal inside the victim's cabinet and attach it to a string. tie the other end of the string to the inside of a cabinet door and wait for your victim to open the cabinet-- the animal will "jump" out on them and give them a good dose of shiver!
Draw a moustache on the face of the person whom you know is sound sleeper ,but while he is asleep! just use an eyebrow pencil or other make-up. no markers! they're too hard to remove!!
Puncture the straw with a pin, then offer it to your victim. they'll suck and suck but will only get the air.
Leave a pack condoms in your girlfriend's purse. and while looking for something in the purse, take out the condom and create scene.
An appliance timer is great fun for anyone who wants to pull a great april fool's day joke. try combining one with several items (radio, tv, bright light, etc.) using a power strip. of course you want to set it up to go off in the middle of the night!