There are lots of different ways to root plants. Rooting powder is used to speed up the process of rooting plants. You put a little on your soil, and let your cuttings root in it for a few days. Rooting powder is used by professionals and homeowners for propagating plants. I have found that the best way to root cuttings is to use a rooting hormone. It is available at nurseries and home improvement stores. Rooting hormone will keep your plants roots healthy and happy. They will be able to absorb nutrients better, they won't get root bound, and they won't dry out. The only disadvantage of using rooting hormone is that it must be used immediately after rooting your plant. If you wait until the next day to apply rooting hormone, it will not work as well. I have seen people recommend using both products. They say that they mix them together and then use the mixture. That doesn't seem like a good idea to me. I think you would need a lot of rooting powder to get any effect.
If you can't find rooting powder, a 1/2 cup of baking soda and 1/4 cup of cornstarch should do just fine.