Books. Books definatly got me out of the 700 USCF range to 1100
I need help. How can I get out of 600 USCF?
I'm a candidate master. All I can say is practice at all kinds of ways. That's what got me to 2100 USCF

Be slow, patient, look for every attacking move and go through your checkpoints for each game. You should also have a sketch of what is going on. Practice endgames and memorise middlegames. Also, have a good chess coach who'll lead you from 600 to 1600. You also have to play a lot, so you get experience.

I would probably say to do puzzles, if you don't have diamond, do them on lichess. After that, maybe look at master games and analyze your own games. Play longer time controls so you can really calculate like 10 min or 15 10. Also try not to blunder however that is easier said than done. This got me from 700 to 1700 chess.com

Find a decent training plan and stick to it. Don't keep searching for the best study plan, that's a mistake many people make. It's all about consistency and quality, not quantity but inconsistent.

I have to agree with the Books I just broke 700 and was 200 last month before I started studying my moves and what causes me to loose especially. Now one thing that helped a lot was Visualization Training, I will be willing to point you to some material if you can't afford any of the courses etc..

Practice solving puzzles everyday. Play longer games instead of blitz so you can think about each move and not blunder so often. Pick your favorite openings for white and black and stick with them...the more you play the same openings, the more familiar you will become with their variations. Review your games to learn from mistakes.
Please help, because I hope I can get answers to break 700 USCF.