I have no experience with Cryptomeria.
I have done Hinoki - Chamaecyparis obtusa. In late summer I just stuck cuttings I trimmed off a tree, stuck them in a pot with a peat-bark mix, and set them in about half shade, morning sun, evening shade. Just left them outside all winter, by late summer they were showing growth, a good sign they had rooted. Success rate was about 25 %. Far from commercial success, which would be better than 75%, but I used zero hormones, no "greenhouse domes" nothing at all. Just simple stick the cuttings in a pot.
I imagine for cuttings, Cryptomeria would be about the same.
I have no idea about air layers, my understanding is that it is possible.