as the beastie boys said "slow and low, that is the temp"
cool, with ~50-60% humidity, or less, unless you can control it more precicesly. If so keep it up near 55-60. Mid to upper 60s F, again if you can. After 3 days you can let it go even cooler by a few degrees.
can line a box with parchment paper and avoid the problems of cardboard absorbing stuff... get a mesh drying rack on amazon? the hangers with the removeable pant clips -- lol - can get quite a few limbs clipped up on hangers in a closet. Anything that allows you to adjust rate of drying easily as needed would work well. Boxes do that, closets.. mesh rack may be too fast depending on environment.