What to do with the layers? Same procedure as every year, put them into water and see what happens. My friend had a much better idea to keep the roots in the dark than my ususal method to put dark paper around them: put the vase into an empty potato chips bag, that's made of opaque foil to keep the light from the chips, and what's good for them can't be bad for new roots, can it? You can cut severals offshoots from one stem, and to keep them from drying or getting infected you can dip the tops into hot wax to seal them.