Put a potato in the exhaust pipe of the car. The car would not start. Paint the potato black so that the victim cannot see the potato.
Rub a baby/massage oil to the taps/window knobs(only the circular types). The victim would find it difficult to open the door or tap.
Tie a knot to the laces of both the shoes with each other. But avoid doing it on elders as they may trip and hurt their fragile bones.
Take a brownie and form it to look like dog poo. Place it on the grass of the victim's yard. As you and victim pass by, point it out to the victim, bend over and examine it. Then grab it and put it into your mouth; or throw it at the victim. The victim will get a momentary shock until they figure out they've been tricked.
Get up early to unplug the toaster. If the cord is normally visible find a cord that looks similar, plug it in and hide the rest behind the toaster. Besides not working, most toasters won't even lock the toast down when you push the pedal. Just make sure you're there to watch your victim become frustrated as his toast keeps popping back up!
Take a picture of the top part of the kitchen counter. Go on the Internet and search for a picture of a cockroach. Then, copy it on to the picture of the counter. Print out a few copies (cut off any extra white space), and place them on the counter. At first glance, your victim will think the kitchen is infested! You can use the pics of mice also.
Go to the video store with the victim and have them pick out some movies they want to watch. Then when you get home, have them go get some snacks or something and while they're distracted, switch the DVDs inside the cases with some really lousy movies you know they'll hate. Then laugh when they think that the video store gave them the "wrong" movies!
Use a universal remote control system and change the channels and adjust the volume while hiding outside the window of victims room.
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!
Post signs on a park bench that say,"Caution: Dry Paint". Sit down next to the sign. Laugh at people who come and try to tell you not to sit there!
Find a small picture of a a funny creature ( monkey , donkey , baboon, etc) and use a glue stick to place it over the photo on victim's driver's license. Then send them out for beer, or have some better excuse to send them somewhere where they need to show their ID.