Cut coleus stems at a slight angle just above a point where two stems branch, to encourage good growth patterns in the parent plant. Use sharp pruners or scissors to make a clean cut.
Remove the lower foliage that would be under water, and place the stem into a jar of clean water. Use a clear jar so you can see the water.
Place the jar in a location with bright light, but out of direct sunlight.
Change the water when it becomes cloudy.
Plant the cuttings in pots filled with general-purpose potting soil, when roots form. Use 2- to 4-inch pots if you plan to transplant them outdoors, or plant several cutting in 6-inch pots if you want to keep them indoors.