Hi! Here are a few things I would consider:
1) Continue doing tactics, those are a must for any level
2) When it comes to improving positional chess, there are a number of methods:
a ) You can look at a variety of top grandmaster games. As you look through a given game, try to guess what the next move will be. If you are correct, try to understand why. If you are incorrect, try to understand why the grandmaster move was better. Sometimes, the reason for the latter my not be extremely obvious; you may need to turn on an engine. When it comes to choosing these games, try looking at grandmasters that you like, or those who have a similar play style. You may also want to look at the games of grandmasters who play the same opening as you.
b) If you do the above, you will understand positional ideas a bit better. This will allow you to save more time during games because the patterns are developed in your head. This means that your tendency to mess up due to time issues will be lessened
3) In terms of books, I would recommend How to Reassess Your Chess by Jeremy Silman. The book covers imbalances, which are a key part of chess. Silman makes it so that players of all levels, though I would recommend being about 1300+. Another book that comes to mind is Amateur's Mind, also by Silman. It talks a lot about positional play.
4) In terms of youtube videos, I would recommend those by youtuber Hanging Pawns. He makes ~half an hour videos ranging from openings to positional play and common attacking motifs.
Hope this helps
First of all, I want to say that I am passionate about Chess. After discovering it 8 months ago, and after playing many games (over 4,5 k) and practicing a lot of puzzles, I went from an initial 800 to a current 1300-1400 rating (biltz and rapid).
I don't care too much about bullet games (which I am awful at, by the way) because I am not (and never was) a fast thinker, and daily games aren't so appealing since people have all sorts of time to move and is not so realistic for me.
I think I am like a semi beginner at some point. I have a fairly decent understanding of tactics and end games.
My main weak spot, and what I think is keeping me from reaching a higher ceiling, is lack of strategy and positional understanding.
I can clearly see the issues when facing an opponent around my rating, with all of our pieces developed and similar pawn structures, then I dont know what road to take. Should I try some bold attacking move? Should I wait and see what he has to offer? Usually I opt for the latter, only to find out after a few moves that he had already thought a plan and had already seen a weakness (or more) in my system.
Another big problem is that I take much longer to think the moves in the middle game, so usually when we are in the crucial parts on the middle game, I either blunder because of having less time remaining (I am talking about 20 or 30 minutes rapid games, and this happens with 5 minutes remaining approximately) or fail to see a winning move.
I have learned a lot from Silman and several Youtube or site videos, exercises and deep analysis of past games, But when I tried to read Positional Thinking by Gelfand, I just cant understand 95% of its content.
So, in the end, my question is. Can someone point me to the right videos, podcasts or books that could help addressing the weak parts of my game and that could be understood by a 1300-1400 guy?
Regards