The easiest way to clone plants is by cutting them with a clean knife. The cut must be as clean and sharp as possible, and the knife should be sterilized before use. Then, you place the cutting in a water-tight container such as a ziplock bag or other airtight container, and keep it on a warm surface. The warmth will speed up the growth of the cutting.
You may want to place the cuttings on a heating pad, or even in an incubator.