The knowing "why and when" is what makes the better player better. Years ago Horowitz wrote "Point Count Chess" which tried to put values for the positional elements. Not a bad book if you ignore the point count.
Best Book for Planning

I suspect you can't do point counts well because is varies too much from position to position. I imagine much of it just comes through bitter experience of choosing the wrong plan based on the wrong assessment. Then even things that are statistically true, like the early pawn gambits being not as sound as normal openings at equal strength master play, are tested on occasion maybe just for surprise.
I was curious so I went to Amazon.com to look up the book. It was written 45 years ago. The reviews said: Skip the point count, and maybe the best first primer on posional elements. The average price was about $20. You might want to check out the book.

For planning? ReAssess Your Chess by Jeremy Silman is probably the best for players under 2000 (OTB).

Silman is coming out with a new edition in a few months. I likely get that version then. I do have his older workbook too.

When I like to plan an attack, I try remember Vladimir Vukovic's art of attack in chess , first edition 1965, then 1968-74-79-82-85-88-91-93-94-95, Algebraic edition:1988-99-2000-01-02(twice)-03-04, now from EVERYMAN CHESS SERIES and it's Chief Advisor: Garry Kasparov, the Great.Let check my library, I may return back. Thanks.
What strategy book has helped you the most? Are there any good books that not only talk about the positional elements but actually compare them. For instance when is it worth to sacrifice a pawn to grab an open file. How would I know that the c-file is going to be more impertant than the h1-a8 diagonal.