Opening plan (Read & learn about opening strategies. The aim is to create a pawn structure for the middle game. Every pawn structure has a strategy. So that pawn structure strategy is part of the middle game strategy.) Think about the 3 golden rules as you try to master the transposing opening puzzles.
lichess.org/training/openingMiddle game is combinations (Master the tactical puzzles.)
Endgame is technic (Master simplified common end games.)
Once you master every phase, it will pretty well boil down to time to play.
Think about the 4 elements as you enjoy the game.
Ever move will affect 4 elements of your game:
1. Squares (Weak move because it was protecting a square before moving. After the move it is protecting other squares.)
2. Open lines (The move opens new lines and closes others)
3. Position (The piece that is moved maybe in a better or worse situation. Like landing on a safe or unsafe square and ends up with less or more mobility)
4. Center (Control it, occupy it and move pieces through it. Using the center is taking advantages of the chessboard.)