Here are little facts and mnemonic devices to help you memorize the First Presidency and Quorum of the Twelve Apostles in order.
1. Monson: His name rhymes with one.
2. Eyring: The first part of his last name sounds like eye, and we have two eyes.
3. Uchtdorf: He was called to the Presidency on February 3, 2008.
4. Packer: The Green Bay Packers have won four Super Bowls.
5. Perry: He was born August 5, 1922.
6. Nelson: He has six degrees (BA, MA, PhD, and 3 honorary degrees).
7. Oaks: The Creation took seven days, and one creation is oak trees.
8. Ballard: Think of the eight ball in billiards, which is similar to his name.
9. Scott: Two parents + seven children = family of nine.
10. Hales: He had ten other major Church callings before called as an apostle.
11. Holland: The two l's in his name look like the number eleven.
12. Bednar: The name David A. Bednar is twelve letters long.
13. Cook: Thirteen is a baker's dozen, and a baker is related to a cook.
14. Christofferson: His last name is fourteen letters long.
15. Andersen: He was sustained an apostle on 4/2/09. 4+2+9=15.
Challenge: Obviously, memorize the apostles in order.
Note: Disregarding the First Presidency, the true order of seniority would be Monson, Packer, Perry, Nelson, Oaks, Ballard, Scott, Hales, Holland, Eyring, Uchtdorf, Bednar, Cook, Christofferson, Andersen.