Combine 2 parts peat moss and 1 part perlite in a bowl. Mix the components together while drizzling water over them. Keep adding water until the components are integrated and moderately moist throughout.
Pack the peat moss and perlite mixture into a 3.5-inch plastic pot. Firmly press the mixture into the pot to remove any air pockets. Poke a 2-inch-deep hole in the center of the mixture.
Harvest a 4-inch-long cutting from the tip of a vigorous and healthy pothos stem. Make the cut with a pair of pruning shears just below a set of leaves. Pluck off the lower set of leaves so the bottom half of the pothos cutting is leafless.
Insert the leafless portion of the pothos cutting into the hole in the peat moss and perlite mixture. Press the mixture in against the base of the pothos cutting.
Place the potted pothos cutting into a 1-gallon plastic bag. Close the bag so it is only open an inch or two for ventilation.
Set the potted pothos cutting in a warm, bright spot out of direct sunlight. Moisten the soil whenever it dries out in the top inch.
Check for roots in three weeks by lightly tugging on the base of the pothos cutting to feel if it is stuck to the soil mixture. Transplant the pothos cutting into a permanent planter filled with potting soil two weeks after rooting.