To take cuttings from mint, use a pair of secateurs and cut a healthy stem from the plant. This should be around 8-10 cm in length.
'Choose a tender stem with three or more nodes (the place where a new leaf will emerge), and strip the leaves from the bottom couple of inches of the stem,' says Daniel Carruthers. 'Then, all you have to do is place it in a jar with around two inches of clean water, which you should change every few days, and place it on a sunny windowsill for a couple of weeks until roots begin to develop.'