most important has to be checkmate patterns and tactics recognition. Most players at the 1700 range play without an end goal in sight, they aim to checkmate but dont know how the checkmate mate will look like. By practicing checkmate patterns or positional tactics, you can slowly mold the game into a favourable position that you want. as you play more bullet the process becomes more automatic and muscle memory. learning checkmate patterns got me from 1800-2200 because i blunder less and i dont miss as much good moves