your tree looks like it could develop some nice aerial roots. Just one question. Any idea how the person who raised this tree got the trunk/root ball to grow? Not that it really matters, but im curious...and i could comsoder growing it with some cuttings i am trying to root.
The man i got it from had been doing bonsai for roughly 50+ years. I spoke with him when I purchased it, and if I recall he did his from softwood cuttings. I think he said that seedlings can take a long time.
Anyways, take a cutting that has several nodes. Cutt of the lowest leaves and the growing tip. Then on the larger leaves be sure to cut half to 2/3 off to prevent too much water loss.
Mostly what i read is to use a sandier soil mix, using a chopstick or equivilant make a hole for it. Put the cutting in about 1/3 its length into the soil.
Id suggest it in some sort of tray with a covering that allows light in to keep up the humidity.