I've also read lots and lots of books through the years. But it depends on how you study. I didn't realize that until I began to coach a high school team and realized the players who spent little time on openings but worked on planning and tactics were the most successful.
We all hang pieces on occasion - even in daily games - one key is to force yourself to look at all your pieces -especially those that are not protected by other pieces - and make sure there's not a fork, discovered attack, etc. that's going to get them. You can do that MUCH more quickly and thoroughly is you know what you're looking for!
In general, I love the guidance throughout the game by thinking about Chessmaster Fred Wilson’s 4 principles from his excellent book Simple Attacking Plans where the 4 principles are demonstrated by 36 annotated games:
I have come to believe there are only four essential, even primitive, concepts which you must learn and understand in order to play successful, attacking chess - Fred Wilson
- In the opening, whenever justified, relentlessly attack the weak squares f7 or f2.
- Most successful kingside attacks are directed against the squares h7 or h2, and they are often preceded by eliminating or driving off its defender. Corollary: most successful attacks require a long queen move.
- If your opponent’s king is trapped in the center, make every reasonable effort to open and dominate the e-file, and sometimes the d-file also.
- If possible, point all your pieces at your opponent’s king.
Otherwise, what helps me see the board better and avoid hanging pieces, etc. is recognizing tactical and positional patterns.
So I memorize and be able to demonstrate by name dozens of tactical motifs and positional motifs. Knowing the positions they require help me see the overall situation on the board better. Here are three interactive sites where I review them every so often:
https://chesstempo.com/tactical-motifs.html
https://chesstempo.com/positional-motifs.html
https://www.chess.com/article/view/chess-tactics
Chess.com has a number of pages and lessons on seeing tactics. IM Danny Rensches 5-part series on Patterns You Must Know is excellent. Also, check out pages like:
https://www.chess.com/blog/IMRonilm1204/improving-your-tactics
https://www.chess.com/article/view/test-your-chess-patterns-and-concepts
The book I love most about tactics is Martin Weteschnik's Chess Tactics from Scratch, 2nd Ed. (c.2012), where he emphasizes patterns - even patterns where the target is an key empty square. He writes near the beginning: "Solving tactical puzzles without fully understanding the underlying mechanisms is not the most efficient way to learn. Instead you must first understand the elements of combinations....[the patterns] might look...trivial...but might turn up in complicated situations. Only if you know these simple patterns by heart will you be able to recognize them in very difficult situations. Have you ever lost due to an unforeseen [tactic]? [From such] games,...put the positions on a board and try to figure out why these [tactics] came as surprises. Don't be satisfied with just being able to pinpoint the exact mistakes. Always try to understand the underlying causes of your defeats. In some sense all defeats are caused by lack of understanding. So the question one must ask oneself after a loss is: What more do I need to understand to improve my chess?”
So, As I watch (much) stronger players play games at my club, I can find pretty strong moves. I was watching an online video and I had the move that a master suggested in that position almost immediately. Somehow, I'm unable to find good moves while actually playing games. I hang pieces, miss one move mate threats, etc. Also, unlike most people, my OTB rating is much better than my online rating. I can't explain it. I have read books, watched videos, studied openings, actually know what each side is trying to accomplish in them but I'm somehow unable to apply this knowledge OTB. What's holding me back?