Regarding propagating a Pakistani mulberry from a cutting off the tree that I'm growing, I found that this video by an AZ horticulturist was very specific and helpful.
Here are my notes:
1. Cutting should be ~thick as a pencil
2. Take cutting during winter dormancy
3. Use skinny (4” x 12”) clear bag
4. Cutting should stick out of bag at top and have ~2” space at bottom
(12” to 16” cutting recommended)
5. Nodes are where roots grow so make sure at least 2-3 nodes on cutting
6. Snip off the cutting below the top (4th) node (use that node for next cutting)
7. Media in bag is vermiculite only (no bugs or bacteria thrive in this) prevents fungus gnats
or sterilize soil 20 - 30 min at 200 degree oven
8. Vermiculite (or sterile potting media) must be damp but not soaking wet (need air and water)
squeeze into clump with fist for right moisture.
9. Fill bag ~3/4 full with space at top to close bag around cutting with a twist tie
10. Score cambium layer with knife (slim vertical peel)
11. Optional: apply rooting hormone (Dip ’n Grow Liquid is what he uses but any brand will do)
12. Gently thread cutting into bag of vermiculite
13. Add additional vermiculite if needed to cover nodes and leave 2" space for bag closure
14. Put in 40F - 50F degree dark place (so plant won’t foliate)
Look for condensation in bag from damp media: no watering needed during this closed bag phase
If the propagation succeeds, bag will fill with roots in 6-10 weeks
After the rooting, plant in pot with regular potting soil