Choose decorative bottles in which to grow mint cuttings. Since mint is long-lasting, the container should be part of an attractive display.
Take cuttings from a vigorously growing mint plant. Cuttings should be 3 to 6 inches long with good leaf growth at the top. The best cuttings are those that break off when bent. Remove leaves on the bottom 1 to 2 inches of the cut. Pinch back topmost growth to encourage new leaves to sprout on the stems.
Place cuttings in containers filled with room temperature water. Water may include a weak solution of houseplant liquid or rooting hormone if it is available. If not, cuttings will root in plain water, often in just a few days.
Place a decorative bottle filled with mint cuttings in a warm indoor location away from direct sunlight. To retain humidity, you may cover bottle and cuttings with a plastic bag that does not touch the leaves, but the mint will grow roots without additional humidity.
Change the water in the container occasionally as it changes colors. This can be limited to once a month in most cases.