How do we improve ourselves?
Here is what I am doing: analyzing every game I lose until I can answer the question for myself "why did I lose?"
I categorize why I lost as either being an opening, midgame (tactical or strategic) or endgame mistake. If I lose in an opening, I follow the opening explorer for that game to find a better line--maybe only 1 or 2 moves deeper than the mistake.
If midgame, I look at how I created the trap I fell into, give it a name, and become conscious about it. I also study tactics daily (here or chesstempo.com).
If endgame, I study how to complete that endgame (or endgame principles) until I feel I understand that.
Every lost game is a chance to learn. Don't waste it!