So, how often do you practice or train?
Me?
As a private citizen, and then as a young cop, I tried to make it to the range as often as I could afford to pay range fees and buy ammunition (or reloading supplies). Once I became a cop I could slip in a little extra range time and make use of the remanufactured ammo we used for revolver quals, as well as attending the 60-odd hours (as I recall) of academy firearms training. As a longtime shooting enthusiast and hobbyist, I was willing to take advantage of any opportunity to shoot.
Once I became a LE firearms instructor a little over 26 years ago I've usually managed to put in 16-48 hours per month of working range sessions and teaching classes, and doing as much shooting for training, practice and quals as was permitted (above being required) while working at the range. That doesn't include going away to attend firearms instructor training & recertification, as well as some outside training involving shooting.
That also doesn't include being unable to shoot due to work-related shoulder & elbow surgeries and some other injuries, and then after retirement having to have surgery and 6 months of chemo resulted in me having to take several months off from my continued instructor duties and being able to do a lot of practice. Sure, I went the range a couple of times during chemo, but the side effects of the chemo sapped my strength and endurance and made me very susceptible to the cold, both of which affected my shooting.
What do YOU think is a minimum for regular practice, or what should be strived for?
For someone else? Hard to say without knowing and evaluating the knowledge, training background, experience and abilities of an individual. Shooting is one of the physical skills that's been deemed to be perishable, so some amount of initial and recurrent "training" and practice regimen is probably going to be required, depending on the level of skills and abilities desired by the individual (or, required of the individual, for professional requirements).
Also, someone just burning powder for the sake of being able to say they're "practicing" doesn't take into account whether they're engaged in good practice, or something that's more of a 'counter productive' endeavor. If they're really just practicing and further ingraining poor skills, what 'good' are they really doing?
I'll start by saying I go to one of a few available ranges at least once a week pretty religiously. If I miss a week I'll go twice the following week. Honestly, if I could afford to I'd shoot daily.
Batter up....
If you enjoy what you're doing as a pastime and recreational pursuit (hobby, etc), so much the better.
In the long run, I've seen people who have been shooting for 10, 20, 30 & 40+ years. Some of them had acquired some very respectable skills and abilities, and some others had merely attained somewhat limited or minimal skills, and had really only been 'practicing' to stay at that minimal level of skills and abilities for that length of time.
This is rather like asking someone how skilled they wish to be in self defense or martial arts. How skilled do they think they
need to be? How skilled do they
want to be? What are the real world demands that might be placed upon them? Are they as skilled as any anticipated threats might require them to be, in order to adequately defend themselves? Are their thoughts, preferences and anticipated risk considerations realistic?
A definitive 'answer' is going to be somewhat elusive and difficult to obtain.