user7066: I am a normal player with ~1500 FIDE rating, and I am quite good at tactics and trap things. But I falter at the positional games and I am bound to make mistakes where the things are non-tactical. So how should I improve my positional chess understanding?

user10659: The first thing you should do in order to improve your positional skills is to read classic books. In my opinion two of the most important books are:
300 Chess Games by Siegbert Tarrash and My System by Aron Nimzowitch. I prefer these books because they could help you to understand the positional laws of chess(the only thing that matters when you face a good player is the ability to estimate an unknown position). 

user20776: For me it was decades of experience and not trying to slash and burn to a win with tactics like I was tempted to do when I first started out.  
Along the way it was examples where I was forced to sacrifice the exchange to avoid worse things,  and discovered that I had a much better position than the material loss as I ended up winning.  Seeing how the minor piece beat a rook in some positions helped me appreciate positional play better.
More recently playing an expert rated player he made less aggressive although not outright passive moves in the opening so I gained some tempi and had more space. Through the game the advantages kept growing until I won. The total lack of tactics and seeing that game as a whole helped me appreciate positional play more and realize that now I am doing more of that and relying less on tactics. 
Takeaway is that is is partially a mindset.  If you do not like positional play and always look for tactics you will not improve your positional play.
You need to learn how pawn structure affects the play and also study endgames which are not as slash and burn tactical as many players prefer in the opening and middle game which distracts them from positional considerations.
Remember if you do not win in the middle game you will have to play the end game.  End games will help you plan ahead in the middle game so that you can do  better.  Often I have not castled and have been able to move my king into the center at the end game several moves ahead of the opponent thus giving myself a big positional edge.

user3529: My suggestion ist to take a book on positional chess and look through it.  For example "How to Reassess Your Chess" by IM Silman is, in my opinion, a good book to get started.  It walks you through all of the positional elements and gives you at least a good idea on what you might want to look out for.  Of course this can only be a start and at some point you may have to look beyond for some ideas on pawn structures, for which also several good works are available.
One word of warning is that, often, while you may feel that the weakest part of your game is positional chess, this might not be correct.  You can be sure only if a show a couple of your games (especially losses or games where you ended up in an uncomfortable position) to a (quite a bit) stronger player and ask their opinion.  
In any case, I would like to recommend also the book series by Yusupov, in particular for your level the Fundamentals series (orange color).  These books contain positional chapters, but also endgame, tactics, openings and much more.  The goal is to raise the level of all your abilities to the same level.  If you can breeze through the tactical parts, this is good for you, then you will mostly gain from the positional chapters. However, it is likely that you will find further parts where you can learn a lot.

7066: <p>I am a normal player with ~1500 FIDE rating, and I am quite good at tactics and trap things. But I falter at the positional games and I am bound to make mistakes where the things are non-tactical. So how should I improve my positional chess understanding?</p>
 10659: <p>The first thing you should do in order to improve your positional skills is to read classic books. In my opinion two of the most important books are:
<a href="http://rads.stackoverflow.com/amzn/click/4871875873" rel="nofollow">300 Chess Games</a> by Siegbert Tarrash and <a href="http://rads.stackoverflow.com/amzn/click/1880673851" rel="nofollow">My System</a> by Aron Nimzowitch. I prefer these books because they could help you to understand the positional laws of chess(the only thing that matters when you face a good player is the ability to estimate an unknown position). </p>
 20776: <p>For me it was decades of experience and not trying to slash and burn to a win with tactics like I was tempted to do when I first started out.  </p>

<p>Along the way it was examples where I was forced to sacrifice the exchange to avoid worse things,  and discovered that I had a much better position than the material loss as I ended up winning.  Seeing how the minor piece beat a rook in some positions helped me appreciate positional play better.</p>

<p>More recently playing an expert rated player he made less aggressive although not outright passive moves in the opening so I gained some tempi and had more space. Through the game the advantages kept growing until I won. The total lack of tactics and seeing that game as a whole helped me appreciate positional play more and realize that now I am doing more of that and relying less on tactics. </p>

<p>Takeaway is that is is partially a mindset.  If you do not like positional play and always look for tactics you will not improve your positional play.</p>

<p>You need to learn how pawn structure affects the play and also study endgames which are not as slash and burn tactical as many players prefer in the opening and middle game which distracts them from positional considerations.</p>

<p>Remember if you do not win in the middle game you will have to play the end game.  End games will help you plan ahead in the middle game so that you can do  better.  Often I have not castled and have been able to move my king into the center at the end game several moves ahead of the opponent thus giving myself a big positional edge.</p>
 3529: <p>My suggestion ist to take a book on positional chess and look through it.  For example "How to Reassess Your Chess" by IM Silman is, in my opinion, a good book to get started.  It walks you through all of the positional elements and gives you at least a good idea on what you might want to look out for.  Of course this can only be a start and at some point you may have to look beyond for some ideas on pawn structures, for which also several good works are available.</p>

<p>One word of warning is that, often, while you may feel that the weakest part of your game is positional chess, this might not be correct.  You can be sure only if a show a couple of your games (especially losses or games where you ended up in an uncomfortable position) to a (quite a bit) stronger player and ask their opinion.  </p>

<p>In any case, I would like to recommend also the book series by Yusupov, in particular for your level the Fundamentals series (orange color).  These books contain positional chapters, but also endgame, tactics, openings and much more.  The goal is to raise the level of all your abilities to the same level.  If you can breeze through the tactical parts, this is good for you, then you will mostly gain from the positional chapters. However, it is likely that you will find further parts where you can learn a lot.</p>
