There are characters in my world who have magic blood that they frequently need to shed for various reasons, including but not limited to - during combat to try to get it on their enemies for some spells, across rooms to lay traps, etc.
Note that volume of blood doesn't matter too much, rather, what the blood touches or what it is near is more important.
However, they still need to be able to fight. They need to be able to draw blood easily and accessibly (say, with a knife, a sharp stone, or if nothing else is available through biting. That would cause a bit too much bodily damage though). And the blood flow should be able to be staunched a short while later, giving enough time to shed the blood and spray it or arrange it or whatever, but not enough time that sever blood loss is caused. Moreover, though regular cutting and damaging would of course leave a scar, no more than superficial permanent damage can be tolerated.
Do note that these blood people have increased blood regeneration and also wound-healing powers. However, the wound healing can only be stretched to a limit and aren't too far above normal humans.
Is there a practical place for these people to reliably cut to draw blood with all the conditions true, or will more handwaving be needed?