How to Study and Improve (Quickly) in the Endgame
I've been blessed to like studying opening variations. I find the search for novelties to be an interesting endeavor. I also like studying tactics and middlegame planning which is the most important part of the game; it's usually when games are won or lost. The reason it's good to enjoy what you study is that you retain what you enjoy at much higher rate than what you force yourself to study.
I'll be honest, I'm not as enamored with studying the endgame. Most of my games are decided before the endgame and it's just not what interests me. For parts of the game that you do not enjoy, it's important to find them in your actual games. How being better at an endgame could have lead you to victory or to a draw instead of defeat. This will make studying the part of the game you do not like more pertinent and more "sticky"; i.e. you'll remember it!
When you study chess, either study parts of the game you enjoy or find a way to make it pertinent so that it sticks in your brain. Below is an endgame I studied that later helped me draw a game I might have otherwise lost, and two puzzles to test your knowledge of this type of endgame. Good luck in your future studying!
Without knowing that White cannot win with 2 rook pawns in a pure Rook ending, Black might not have been able to save this game. It's important to know such theoretical details. Find books, documents, anything to find these theoretical findings. It's more important to know these things than to see Bobby Fischer outplay a GM in a complex ending, where you don't really get the point of what is going on. After knowing that White (or Black) cannot win with two rook pawns try to solve the next problems.