Taking cuttings from impatiens, or many other annuals, is easy and can help scratch the gardener's itch during the off-season. The key is the donor plant that you must remember to bring indoors before the frost kills it. Beyond that, the process is fairly cheap and easy.
mature, donor plant
plastic 4 or 6-packs
scissors, box cutter or other sharp knife
Perlite, Vermiculite or sand
Step 1: Taking the cuttings
Select branches from the donor plant that are 2-3" long. If possible, take the cutting above a leaf so it will grow to eventually form another branch. Use a sharp scissors or blade to remove the branch. Continue to do this until you have enough cuttings or the donor plant has no more good ones. Keep the cuttings from drying out if you can't plant them right away.
Step 2: Pruning the cuttings
Remove all of the lower leaves, any buds and any blooms. Leave only 2 or 3 leaves at the very tip of the cutting. If a leaf is bigger than a dime, cut off half of it. There are no roots for the first couple of weeks and the new plant can't support much top growth