The easiest way to improve is to stop giving games away. Blunders usually come from rushing, tunnel vision, or ignoring the opponent’s plans. Prophylaxis — thinking about what your opponent wants — is the antidote.
After each move, ask what squares or lines opened or closed. This simple question prevents oversight of new threats.
Unprotected pieces are tactical magnets. Before every move, glance at what’s hanging and ensure all defenders coordinate.
Make sure your own king and pieces are safe before launching aggression. Good defence is the foundation for good attack.
If a position suddenly opens or a trade is offered, take a few extra seconds. Most blunders happen during transitions.
Prophylactic thinking means respecting your opponent’s ideas as much as your own. Cultivate awareness, and your mistake rate will drop dramatically.