A good way to encourage root formation and keep them turgid is to moisten a paper towel, put it in a gallon ziploc bag, and put your cuttings in. Blow up the bag, seal and wait. I kept that microsorum linguiforme alive 6 months in a bag before I used it, same for a lot of peperomias and ficus. Occasionally mist the towel, and blow more CO2 into the bag. I actually get really good results with this method.