Sites like lichess allow you to run a computer analysis of every move so you can find how often you made what the chess engine considers the strongest move. It will also clearly show you any blunders regardless of whether your opponent took advantage.
Further, you can easily compare your responses during openings to what master level players play and you can also just look at how effective certain opening lines are just for your own games.
Lichess also has an "insights" feature where you can look at all your games in aggregate and ask questions like "how often do I win playing Ruy Lopez opening compared to when I play the Italian opening", etc.
These sites also have endless tactical puzzles which you can practice with.
I guess deliberate practice to improve consists of some or all of these tools plus studying certain aspects such as end games and openings.
I'm too impatient to do any of these which is why I improve very slowly despite playing thousands of games.
Further, you can easily compare your responses during openings to what master level players play and you can also just look at how effective certain opening lines are just for your own games.
Lichess also has an "insights" feature where you can look at all your games in aggregate and ask questions like "how often do I win playing Ruy Lopez opening compared to when I play the Italian opening", etc.
These sites also have endless tactical puzzles which you can practice with.
I guess deliberate practice to improve consists of some or all of these tools plus studying certain aspects such as end games and openings.
I'm too impatient to do any of these which is why I improve very slowly despite playing thousands of games.