I'm really grateful this forum exists - and I want to thank everybody for sharing cuttings & experience. I'm a new fig nut still learning the ropes. My first try last year with cuttings from a local exchange was a disaster. Out of about 10, none survived. I used perlite, rooting hormone and bottom heat.
Since then, what works best for me is Jon's small plastic bags (u-line) method. As the rooting mixture, I use fine bark (3-4 handfuls), peat (1-2 handfuls) and perlite (1 handful). To this, I add a spoonful of dolomitic lime, and enough water to moisten it (so it barely sticks together). I bury the cutting leaving only 1-2 inches above, or even less if the cutting is short. I put all the bags in a plastic container that I keep covered. Twice a day, I fan the box with the cover. I keep the box in a cold-ish room (55-65). That helps the cuttings not leaf out too early, and minimize mold. Once I see new growth, I move the box outside in the morning (with the cover off), so they get used to the sun and I don't have to worry about that once they have several leaves. It also helps that days are cool (60-65) and humid, but I also spray the leaves with water. If I see the top inch of dirt dry I add/spray a little bit of water.
Once I see decent root development, I pot them up into 1 gallon pots, in 100% miracle gro moisture control (but this year I'm trying 1/3 bark, 1/3 miracle gro, 1/3 potting soil) and out they go on the deck (but we have mild summers here, rarely above 80)
I got about 50% success, but that has proven more than enough for me. I ended up with about 30-35 treelets last year, and probably the same this year (I'm in the process of up-potting the first rooted batch). I almost never get mold (unless the cutting was moldy to start with), and if they fail, in 90% cases the cuttings just shrivel up with no roots for whatever reason: failures mostly happen in the baggie (last year I only lost one after potting up) I'm sure this can be improved substantially, but it works out pretty well for me.
I think the key is the bark. It keeps the mixture aerated, can soak up excess moisture and regulate humidity, and I suspect it may have some chemicals that keep disease / mold at bay. I love bark! :)