Fill the individual containers with rooting medium. If you are using small pots with saucers, place the pots on their saucers. If the pots don't have saucers, place them on a tray.
Moisten the rooting medium thoroughly. If water runs out the bottom of the container, empty the saucer or tray. Don't leave the containers sitting in water.
Use scissors or pruners to take 1-inch cuttings from the tips of the New Guinea impatiens stems. Cut just above the point where a leaf is attached to the stem.
Remove any leaves attached to the lower half of the cutting. Make a hole in the center of the rooting medium with your finger and insert the lower half of the cutting into the medium. Firm the soil around the cutting with your hands.
Cut the soda straws in half and insert them in the soil around the edges of the container. Place the plastic bag over the top of the containers. The soda straws hold the bag away from the cutting.
Remove the plastic bag when roots form. Root formation takes one to three weeks.