How do you analyze your own game?

I think this guy on chess dojo is on to something important (see link) and I've been hearing about this for years, but have not done it.

How does anyone find improvements in their own game if they don't know what the improvements look like? How can one trust their own analysis is correct, and not just another mediocre set of moves?

YouTube

She is right.
A computer can find tactical mistakes but you need to learn strategy and how to read the position with independent thought.
Like...how to attack a pawn chain properly.
...controlling the center.
....attacking the center.
...obtaining a knight outpost.
...good bishop/bad bishop.
...ranks and files.
...Opposition...etc etc. And a whole lot more.

The position tells you what move to make but you don't know how to read the position. Chess is not just tactics.

If you really want to get above 1800 at your age you need a coach.