I prefer to root plants in a good potting mix, rather than water.
If you have a leaf of the snake plant, you can divide it into 2" long sections simply by cutting through it crosswise. Dip one end of each section in a rooting hormone, then plant it about 1" deep in a container of soil. The sections will root without the hormone, but it takes longer. Each 2" section will produce a new plant.
Is your dracaena cutting a tip cutting? In other words, does it have leaves on one end? Or is it just a section of cane? If it's a tip cutting, you can just plant it in a good potting mix, and it will root. Do not
use a rooting hormone with dracaenas.
I prefer to start cane cuttings in moist sand. Cut the cane into sections, each with at least one node. (I personally prefer to leave 2 nodes per section of cane.) Allow the sections to air dry, out of direct sunlight, for 24 hours, so the cut ends callous over. Bury them on their sides in the moist sand, but do not cover them entirely. You should be able to see a narrow strip of the surface of the cane section in the sand. It takes awhile, but each section of cane will eventually start a new plant. Again, do not use rooting hormones with dracaena.