Step 2: play video games that reward deliberate practice and skill
Step 3: put in effort on reducing lag, especially if you're playing games developed in the time of CRTs. Modern games are built and tested with modern everything and you get more time to react to things, but games built for CRTs expect nothing more than a couple gate delays between the video out and the electron beam, and for the inputs to be current when sampled. Modern displays have a lot of nice things (convergence is great, vertical and horizontal alignment is perfect, the picture size doesn't change when the background gets brighter or darker, etc), but they usually also have an image processing pipeline that's measured in milliseconds, some take much longer than others. Bluetooth controls use bluetooth, enough said.
Wired controllers and a CRT won't make you good, but flakey wireless and a laggy LCD might make you bad.
Step 4: make a practice plan and use it, and adapt it as necessary.