I nearly always check zero on calipers, dial or digital, before every measurement. If they have left my hand, zero gets checked before the next measurement. I was trained to do that and it has become habit, one that I think is a good one to have.
Read on for a bit of a bio, maybe it adds context to my posts:
I'm not a Journeyman Machinist, I don't have the depth of training for that as that properly is years of apprenticeship. I did work as the "special projects" machinist/fabricator in a racing engines machine shop and under a retired Tool & Die machinist in a Vintage Racing & Touring car restoration/preparation shop during my undergrad years and for both on occasion since earning my Engineering degree. I think that I was about 7 or 8 when I made my first metal lathe project. That was more than a few decades ago.