Returning to a theme that remains popular with my readers.
Next time you see a position that is supposed to be winning: capture the position, transfer it to your favorite chess program, set the program at a higher rating than your own and play the winning position to see how to conclude the game. Then go back and repeat the exercise at an increased rating until you can win against it at full strength.
The position below is from a practice game. I missed the Knight sacrifice during the game, but in later analysis, I immediately recognized the winning technique. I eventually won the practice game, but it took many more moves.
For readers who wish to try this exercise, the FEN is:
8/6pp/8/1pn5/8/PPk4P/2P3P1/3K4 b - -
It is not enough to just know your simple endgames. You must also be able to recognize positions that can simplify to those simple, winning endgames.