A clean environment is pretty important to preventing mold as well. No spores no mold. I lean towards higher temps and rh like mid to upper 60's for both, but my local is very arid.
Watch for cold fronts during drying as they can drop the dew point very quickly outside. As that air gets heated indoors the humidity drops dramatically. The capacity for air to remove moisture from your herb is increased and you can end up with very crispy buds.
