study your opening using databases, do more puzzles, learn more lessons, learn more tactics.
The Best Way To Get Better At Chess Fast

Choose a couple of openings for black and white and try to perfect them. Don't yolo or learn a lot half baked. And puzzles of course.

My friend is struggling to become better in chess, any tips?
study basic tactics, drill it over and over by studying positions and doing copious amounts of puzzles. Make sure to analyze every game, even if you run out of game reports, just analyze it with the engine to know what the best moves are and where you messed up.
play many many games, analyze mistakes. and @CheezeeeBoi i prefer not using engines cuz they don't tell you the meanings behind the moves. oh yeah tactics and study grandmaster games and try to learn from the gm games. maybe 50-100 gm games per year and you will improve quickly.

It really depends on your friends rating. If he is fairly new to chess stick with puzzles because tactics will advance their rating further in the beginning. Also tell them do not get caught up in memorizing a ton of openings. If they use books or material look at attacking patterns or middle game ideas. Next get in the practice of good habits such as looking at his opponents move and looking at the idea and consequences of the move before making their own move.

I think the best way is to study tactics constantly and play games. While you're at it also watch endgame videos - they help a lot

Go over your games and find out what your most consistent mistake is, whether it's missing tactics, hanging pieces, or blundering in the opening. Then try and learn how to fix it.

Everything above is great, but you shouldn’t neglect middlegame concepts, ideas, plans, strategic thinking, positional goals, common themes in the opening of your choice, and all-round endgames. You can play a perfect opening but fall apart immediately once you’re out of the book. Books are great ways to improve. Puzzles, studies, and compositions are all good ways to sharpen your tactics. Like people have said, try to create a flexible but reliable opening repertoire choosing lines that fot your style and preferences of play. Practice and study those openings. To round it all up, use what you’ve learned in practice, playing regularly. Around one longer game a day, like 30|0, 15|10, or longer is good, and personallu it helps me to play some speed chess before and after to warm up, cool down, relax, and just have fun. After playing, analyze your games and learn from your mistakes. Studying master games on certain topics you want to improve is helpful too.

Practice 1-2 move tactics and play longer time controls. Analyze your games to learn from your mistakes.

play many many games, analyze mistakes. and @CheezeeeBoi i prefer not using engines cuz they don't tell you the meanings behind the moves. oh yeah tactics and study grandmaster games and try to learn from the gm games. maybe 50-100 gm games per year and you will improve quickly.
i meant just looking at the lines and analyzing it yourself. That way, you can see your mistakes and see what you missed. But your right, don't rely on engines 100% of the time.
1. Play games
2. Always analyze them
3. You can add them to your library if they are very good games from which you learn a lot.
4. Puzzles, obviously
5.Study oppenings. Study them good, not just 3 moves deep. Check out unpopular lines too
6. Practice midllegame
7.Practice endgame (its hard to learn, worth it tho!)
8. Its always good to play against a computer, for example deep fritz. Give yourself a queen more, than rook, bishop and you will see progress.
9. Watching commentary of better players, dont just go thru it tho, make shure you understand it.
10. Enjoy chess and love it, you wont make progress if you play it without liking it
I hope this helped!
My friend is struggling to become better in chess, any tips?