Why is my tactics spidey-sense not working? I have done over 5000 puzzles on chesstempo but still can't sense any tactics. So for the past few days I've been making a mental note each time a signal appears (loose pieces, exposed king, potential for double attack, etc.) and try to think of a way to exploit it but to my surprise, I can't find any. What I envisioned when I started doing tactics was that I would reach a point where the tactics would come automatically to me whenever I play a game but that point never came. Although I started doing the mental note thing a few days ago, is there anything I can do to improve it?
Developing tactical ability is a long process. At first you expose yourself to new patterns, try to understand how they work when they are already on the board. You will still not spot it every time it appears in your games. But sometimes you will. And sometimes you will see that you or your opponent cannot play a move because it fails due to a tactical motif you know.
The next step is seeing the potential motif long before it appears and setting it up. It is good that you note weaknesses in your opponent's position. This is the first step towards setting up tactics. You see a loose piece, you position your pieces so that eventually you can exploit that.
It takes a very long time from knowing a pattern to setting it up yourself. Be patient. Sometimes I see a tactic by GMs and I can barely solve it with all the pieces already in position, and then I realise they saw it 10 moves ago and played towards it and all I can do is hold my head.
It may be the case that your training method is not suited for you. Studying random puzzles, not sorted by patterns or some overarching theme, may not be good for you. It is good for pure calculation, but not when you are trying to develop your pattern database.