I have posted parts of this I think before , but let me summarize:
I use either very large zip lock bags or very large plastic tubs with clear lids (the type used for large catering events) and use long fiber spag moss that is very damp but not dripping and surround the cuttings in the bags or tubs. The larger the tub the more space between cuttings is good because they tend to grab onto the moss in every direction as the roots grow out. I put these in a dark warm location typically in a closet or kitchen cabinet. After about 3 - 4 weeks they tend to have at least 1/2 in spurs if not a ball of roots at the ends. I then place them in a clear cup in pure moss, and a inverted cup taped in place as a top hat to hold the humidity up. Another month they tend to have leaves and a good set of roots throughout the plastic pot. Different types and various cuttings have no leaves or many leaves depend ant on the vigor of the cuttings more than anything else. If they show leaves I remove the top hat inverted cup. The entire set of cups are placed on orchid humidity trays with 360W of T5 lights about 10 inches above them. I water daily with distilled water ( mainly because my carnivorous plants that are with the figs need only that) Ones that develop to the point of the ones shown today are migrated to 1G nursery pots. About 3 weeks prior to moving out of pure moss, I fill the top of the plastic cup with a 50/50 mixture of African violet perlite fine moss mix and orchid bark mix. The moss is left very loose to allow air and visibility. When I pore the soil in it slowly filters down to the lower levels, but the lower section of the pot is still pure moss. If you look at the picture I posted for Vince you can see this. The roots need a "passive" introduction to soil like media in my experience so this step helps prevent root shock and leaf drop common in the migration to the 1G step mainly due to the drop on localized humidity levels at the roots. In previous years I have gone to soil mixtures right from the rooted stage in the zip locks and it is fine but much slower root growth and leafing. Two months in pure moss allows me to regulate the humidity levels easier and allow them to grow a robust set of roots which I think is key to later season success and vigorous growth. If I did this inside a well heated greenhouse or a location with grow lights and a higher regulated humidity level I would have no problem going to soil much sooner. Nothing magical or right or wrong just what I did.