We asked the BuzzFeed Community for some of their funny, dirty, and most creative mnemonic devices. What are mnemonic devices? They’re useful little tricks or methods — like acronyms or poems — that help them remember important information. Here are some of the best:
1. The order of planets from the sun:

2. The order of the cell cycle phases:

3. When to use "gray" or "grey":

4. The order of mathematical operations:

5. When to use "affect" or "effect":

6. The order of taxonomic rank:

7. How to remember who is on which bill:

8. How to write "b" and "d":

9. How to remember sin, cosine, and tan:

10. How to spell "necessary":

11. The carpal bones:

12. The difference between stalagmites and stalactites (aka mineral formations in caves):

13. Time zones in Canada:

14. How to set the table:

15. The order of the cranial nerves:

16. The order of the first five books of the Old Testament:

17. How to spell "desserts":

18. How many days are in each month:

19. The order of the Great Lakes:

20. How to do multiplication with decimals:

21. And finally, the four principal compass directions:

Note: Submissions have been edited for length and/or clarity.
CORRECTION
Oops! Hamilton and Franklin weren’t presidents. ♫ Never gonna be president now, never gonna be president♫. No. 7 has been updated accordingly.