Mint is one of my favourite herbs in the garden as it is a very vigorous grower with many culinary usages.
What you will need:
1) A very sharp knife or scissors and make sure the blade is sanitized to prevent any pathogens from infecting the potential cutting or plant.
2) A healthy plant to take cuttings from. It is my personal practice to do cuttings from plants that have been watered at least 30min before so as to ensure maximum hydration of the potential cutting(s).
3) A small glass of plain water with neutral PH.
For the cutting, ensure the cut is made around 1/4 inches beneathe a leaf node. A slanted cut is preferred as some believe this can enable more water to be absorbed by the ‘rootless’ cutting due to a bigger surface area. Some rosarians even advocate the practice of cutting underwater (the stem, not the rosarians :P) to prevent any air bubbles from entering the freshly cut stem, thus preventing water from being absorbed efficiently.