These come in various sizes. I recently used several of the smaller ones on a backpacking trip over some blisters and they worked great. They have a very thin margin, which I think helps prevent the edge from being lift by rubbing on a sock. They held up very well in my experience and I see they have larger sizes that I plan to buy for my kit.
A non-adherent pad and some cushion, secured with Leukotape would be my go-to. Leukotape has blown my mind and changed everything I know about foot care and blister prevention.