Step 1: Select your plant, make sure it is big enough. Each cutting will need at least one leaf and one node. And you’ll want to leave at leat some of the plant to grow back.
Step 2: Take a sharp knife and cut between the nodes, they are sometimes large enough to make the cut easily, and sometimes they are close together so you can have to be really careful using a sharp knife. Try to cut them in the middle equally between the nodes.
Step 3: Leave the cuttings aside for at least 3 or 4 hours so the wounds heal over. This is so that the open cuts close up, which will reduce the chance of rot as the would are sealed and do not go soggy.
Step 4: Take the cataphylls and any other organic material you can off the nodes, as this can rot in the water and cause the water to turn cloudy and the rot to spread. You can see in the image below on the left that there is organic matter around the nodes that is not needed, and in the right hand image I have remove it carefully so as not to damage the roots. This helps to avoid rot or the water going cloudy.
Step 5: Put the cuttings in a jar and fill it with water. Keep it well lit but no direct sun, and keep it warm and humid to encourage rooting. It should start to root with in a week and have well developed roots within two months. You can keep them in water if you like (just keep the water topped up) or pot them up into soil or leca to grow them on.