Hiya!
I use the following:
Short Rest: You can use your HD, but the maximum on each die is half it's potential...unless you expend one 'use' of a Healing Kit. Someone with Medicine skill can make a check, and use 'make-shift healing kit stuff' (torn up bed roll, some rope and a bit of the dwarf's vodka, for example), with the DC being dependent upon where the triage is taking place, and what materials are being used. Only one "healer kit usage" needs to be used, regardless of how many HD's are being used by the character.
Example: A Fighter is down a bunch o' HP. He decides to use all his remaining HD...3 of them...because he has no healing kit, nor does anyone else in his party. His CON is 14, for +2. He rolls 3d10, but each die has a maximum of 5. He rolls, and gets 10, 8, 4; he heals 5+2, 5+2, 4+2, for a total of 20hp's. If he had one use of a healers kit available, all dice are normal (and he would have healed 28hp's).
Long Rest: At the "morning", each PC gets to roll a "free" half-maximum-HD, round up. If the area resting in isn't "suitably safe and comfortable", then the half-max-die kicks in. Use of a healing kit ONLY counts for 'actual HDs spent healing', not the 'free ones'.
Example: The Fighter above gets more hurt and the party decides to rest up for the evening. They backtrack to an out of the way cavern with a pool of water. It's a bit brackish, and the whole area is damp and cold. The party decides against any sort of fire, as they don't want to alert anything nearby...so the DM decides this is not 'comfy enough'. The 'night' passes by uneventfully. The Fighter is 5th level, so he gets to roll 3d10+6...but each d10 has a maximum roll of 5. He gets 10, 5, and 1, for 5+2, 5+2, 1+2 = 17 of 'natural' healing. He regains his single HD for having a Long Rest, and decids to spend it immediately. The same penalty applies. He rolls and gets a 9...which becomes 5, +2 for his CON adjustment gives him another 7hp. If the party had a healers kit with at least one use left in it, he would have healed 17, but then healed another 11 (the 9 he rolled stays a 9, but the 'free HD healing' don't get the benefit).
As for dropping to 0hp...we also add 1 level of Exhaustion to the character each time it happens. That said, I am thinking of implementing a rule that allows someone with Medicine and a healers kit to make a check (DC to be determined), with success indicating one level of Exhaustion is removed. Not sure how long this should take...maybe a Short Rest? I'll have to think about it.
Lingering Injuries? Naaa...we just kind of free-form it. If some particular action resulted in significant damage or a really unusual failure, we apply basic "imaginative role-playing restrictions" (e.g., Ohoooo....a 1! So, you swing on the rope, but let go too soon and rather than land on your face you get your forearm out just in time! Your (rolls d6...) left elbow is sprained/twisted. Then the player just role-plays the injury and I take that into consideration when the PC needs to make checks and stuff.
^_^
Paul L. Ming