Openings plans

I am fairly advanced player by chess.com standards (former CM, about 2300 in blitz and bullet online), but lately realized my complete lacking of understanding of strategic plans in different opening systems, especially for black. 

Can anyone recommend a source with ideas overview for different openings? Chess.com opening lessons are for absolute beginners unfortunately. 

Also, can anyone recommend some low-theory setup with simple and clean plans (like London system for white) to test?

Flores Rios - Chess structures is a good book. It doesn't teach you opening theory but the possible plans based on the pawn structure.

Most pawn structures can be reached via different openings but then the possible plans, pawn breaks, outposts, etc are similar

Thank you, I will surely check this book.

have you looked at GM Duncan suttles' games? They're quite unique.

Maybe a little passive, but if you want a low-theory opening against 1.d4, you could go for the Old Indian (1.d4 Nf6 2.c4 d6 3.Nc3 Nbd7 intending 4...e5.)

Against e4 I really can't help you.  As one that plays e4, and knows all the possible defenses, only 4 of them are good, and they are all theory-ridden:

1...e5

1...e6

1...c5

1...c6

The other 16 responses are all weaker (to varying degrees, like 1...a5 is worse than 1...g6).

I wholeheartedly agree with this recommendation. This book, "Chess Structures: A Grandmaster Guide", has separate chapters on the pawn structures that arise from specific openings. It discusses the plans for each side and gives illustrative games, well annotated. It is also very good at the relatively subtle issue of structural transformations. 

#1

"lacking of understanding of strategic plans in different opening systems"
++ "My System" Nimzovich. 

"low-theory setup with simple and clean plans"
++ Birmingham Defence 1...a6, as Miles used to defeat Karpov. In the 2021 TCEC engine vs. engine superfinal both games with it were drawn, so it is more solid than people think. The simple and clear plan is to contest central square e4.
https://www.chessgames.com/perl/chessgame?gid=1068157 

Thanks I will give this system a try. Actually there is similar and quite popular system in bughouse) 

My System -  I have read it multiple times years ago, but I think it is quite outdated and a bit biased to his ideas, although still can be recommended to beginners of course.

Cant agree more, the only problem you need some healing from bughouse afterwards) 

Tbh i play the takatower which is an opening after d4 nf6 e6 then u  want to play d5 and i like to fianchetto the bishop its a very good opening I’m winning 60 percent of my games and I’ve seen akanemsko who is a wgm play it and u dont need to know any theory to play it tbh

Sorry but on 1500 level you dont really need any opening theory to win. It starts to become really necessary above 2000, maybe higher, because you just dont get out of opening without strong disadvantage otherwise.

#9
Very good, but more advanced are books by Mikhalchishin
https://www.goodreads.com/book/show/31293737-isolated-pawn 
Also very good but more advanced: "The Method in Chess" Dorfman
https://www.goodreads.com/book/show/163329.The_Method_In_Chess 

IMO this provides the best elucidation of themes and plans for most of the major openings, and for opening play as a whole.  John Watson's acclaimed four-volume series..

Mastering The Chess Openings by John Watson...

https://www.amazon.com/Mastering-Chess-Openings-Unlocking-Mysteries/dp/1904600603/ref=sr_1_4?crid=2VDV7VWPH1N79&dchild=1&keywords=mastering+the+chess+openings+watson&qid=1627776656&sprefix=mastering+the+chess+openings+w%2Cstripbooks%2C218&sr=8-4

http://www.gambitbooks.com/CompleteBooks.html

an excerpt from Volume 1...

http://www.gambitbooks.com/pdfs/Mastering_the_Chess_Openings_volume_1.pdf

Introduction To The London System & Jobava London System...

https://www.chess.com/blog/RussBell/the-london-system

https://www.chess.com/blog/RussBell

I started reading this book and it seems exactly what I need right now. Thanks again for recommendation. I give a try to other books mentioned later for sure.