I only hit a few balls every day slowly trying to play again after 20+ years of not playing. My wife came down to watch and first thing she said I wasn't getting down on the cue like I used to. I said I need to video me so I can see myself so she'll set up her tablet for me. I immediately went to one handed aiming and got low on the cue and balls were going in like they used to. After a few minutes I added the bridge hand and made some shots that I hit good and it felt good. I'm not rushing it and starting back isn't an overnight thing and hopefully I'll get into some form.
I took a long break and then started again about 5 years ago. I quickly saw that I was not as good as I had been, and seemed to hit a plateau quickly and was not improving no matter how much time I put in at the table.
Finally arranged private lessons from a pro (Jerry Briesath in my case). Jerry pointed out numerous flaws in my routine, stance and stroke.
Long story short, my game was not going to improve until I abandoned everything I'd been doing for 50 years and started over. It took a couple of years, and another session with Jerry, but my game finally started to improve about a year ago, and has steadily improved to the point where I'm shooting the best pool of my life at age 76.
Right now I still need to concentrate on my PSR and stroke or I fall back into old habits. I hope to get everything Jerry taught me built into 'muscle memory'. But until then, my limitation is concentration.
Hope this helps.