First, my "serious" rating with another postal organization is 2021. I went from about 1600 doing the following: Play over a couple hundred UNANNOTATED master games using 5-10 min a game & trying to guess the next move. You are going after quantity here. This reinforces pattern recognition; this is how GM's play simuls so successfully...they recognize patterns and know what to look for. US Master Ken Smith used to recommend this.
Next... (1) Only consider the first 2-3 moves that pop into your head (2) Only look 3-4 moves deep. If you don't see how it loses a piece, play it. (3) Pick the move that looks the most threatening, even if it’s only in a general sort of way. (4) After your opponent moves and before you move, scan the ranks, files and diagonals.
You will then find yourself improving because you start zeroing in on opponent’s weak squares, loose pieces, things like that, and that is what chess is all about – pattern recognition and tactics; at least below Master level.
You may also want to read Search for Chess Perfection by Purdy. It's a collection of his magazine articles, so you can open it up anywhere and find some really good advice.