If one of your is really messy then you can try this prank on them. It actually happened with me and believe me it works!! If the person concerned just doesn't clean up his or her mess and from table or bed and you really find it irritating since that is the situation with most of us when we live in school or college hostels or when we share a flat. So to teach a lesson stick a sign on the bed and the wardrobe, which would say that the wardrobe and the bed are meant for piling waste and when guests come in show her room and bed as the trash bin.
You can also try a prank on your friend who sleeps a lot. You can just carry that person out of the bed to the school ground or college campus or any unlikely place for that matter so when he or she wakes up would find himself or herself gathered by a huge group of people.
You can also try this toilet prank. Put gelatin in the flush when you are sure that the victim would not use not for around three to four hours so that the gelatin solidifies. So in the morning when the victim uses the commode and tries to flush it out he or she would only see his deposits floating. I can assure you that it is going to be scary though there is nothing to worry about because you can break the gelatin and the flush would start working again.
You can also try the glue prank on your victim and put some glue on the slippers of your victim. Let him or her wear it and then can have fun watching him or her trying to get rid of the slippers.
You can also try some insect pranks on people and to do so just buy some insects, which come in various designs to facilitate various kinds of pranks like the you can put them in someone's food or if it is the ice cube fly you can put it in someone's drink. You can also get glowing insects, which you can use to scare somebody in the night since there are always stories of ghosts in school and college hostels.
You can also try this classic yet silly prank on somebody. This requires only few alarm clocks on which you need to set a time and hide them in various places of the room of your sibling and watch the fun as he or she tries to shut them up in the middle of the night.