The View from 1000
... is Hazy
Most of my recent games have been decided by early blunders: hanging pieces, putting oneself into a fork, getting one's own pieces trapped. And most of these have happened early in the game, so there haven't been a lot of instructive moments, except how to play when one is way ahead or way behind. Eventually, this particular game was also decided by blunders, but since they happened toward the end of the game, there were actually a few instructive moments during this one. Among them: make sure a trade is in your best interest.
Lessons: Games at my current level are still often decided by blunders: hanging pieces, getting one's pieces trapped, moving one's pieces into a fork--or failing to take advantage of these. So continued tactics training and conscious awareness during a game about where one is putting their pieces are obviously still in order.
But the main lesson for this game is about trades. White willing offered an early Q trade that gave Black a long-term structural advantage. Later, Black declined to trade f-pawns on e5 that would have opened lines for his R and two Bs, which to that point were hemmed in. Instead, Black willing traded away his long-term structural advantage, the B-pair, and the c-file just for the chance to "do something" on the a-file.
As Maurice Ashley puts it, trade only when the trade is Forced, Fantastic, or ...trying to create mayhem because you are way behind.