Analyze your own games as well as games of stronger players. This helps you understand your mistakes and learn new ideas.
Solve a variety of chess puzzles. This helps with pattern recognition and improves your calculation abilities.
Be consistent with your study routine. Daily practice, even if it's for a shorter duration, is more effective than occasional intense sessions.
Regularly review your study plan and assess your progress. Adjust it based on your evolving needs and weaknesses.
A lot of higher rated players tell me to implement a “study plan” into my daily chess routine. Numerous 2000+ elo players have told me this when I ask them how to improve my chess game. Most of them have failed to mention what I should do when I study. So, with that in mind, here are some questions that I have for people who have them:
What should a study plan consist of?
How long should I study for?
How often should I study?