One thing I started doing the last time I picked up guitar again, which was about two months ago, was wearing disposable nitrile gloves on my left hand. They're extremely thin and durable, and have minimal impact on dexterity, but allowed me to practice for over an hour a day with no residual pain the next day. It was always possible to practice through the pain on one day, but where I would slip up is skipping a day because my fingers still hurt. (And skipping a day turns into two...) I've still developed calluses, too, but I'm not quite ready to give them up. I'm much happier with my progress than I was any previous time, probably because I never skip a day of practice anymore.
It's not the most eco-friendly thing I've ever done, but I figure it's a pretty small amount of plastic in the grand scheme of things (especially in my line of work).