For melees, and some casters, without UMD, there are basically two choices for self-healing without a hireling: CSW pots, and Silver Flame pots.
The difference of effectiveness and efficiency between these two sources is huge. Silver Flame aren't easy to get, so many players are stuck with CSW pots.
My suggestion is simple: make potions of Cure Critical Wounds and Heal drop in chests, much like Mnem pots do. Perhaps give them a high CL, too.
While you're at it, consider potions of FoM, Deathward, Restoration, etc.