1. Show them how little you care about their low blood sugar by wasting their supply of Cheetos.
2. Buy them a kitten who only likes to nap on keyboards.
3. Burn their car to the ground, make it look like an accident, then stand helplessly nearby with a hose and a sympathetic look.
4. Bring this cake to their family birthday party.
5. Grease their gymnastics bar with butter right before competition time.
6. Set them up for epic failure.
7. Leave this for them after a large dinner of chili con carne.
8. Let a Dilophosaurus move into their mailbox.
9. Replace all of their tasty Starburst flavors with lemon. 🙁
10. Make all of their coworkers uncomfortable to be around them.
11. Pretty much destroy their sense of trust.
12. Slip this brochure for Botox under their door, so when they wake up it’s the first thing they see!
13. Trick them into thinking they’re about to have the best night ever.
14. Sign them up for a free subscription to Cat Facts.
15. Make their commute a little sweeter by giving them a fun new paint job using all of their Post-it notes.
17. Contract a really bad cold, then sneeze on them.
18. Book them a flight next to a toddler with sensitive ears.
19. Fill their sink with hair from an undisclosed location.
20. Make their bikini season more distressing than it already is.
21. Buy them generic brand cereal instead of the real deal.
22. Turn their lives into a world where they can’t ever hope to escape Nicolas Cage’s gaze.
23. If all else fails, make them a fruit plate that only consists of cantaloupe and honeydew.
Read more: http://buzzfeed.com/erinlarosa/23-effective-ways-to-tell-someone-you-hate-them