Blindfold one person at a time. Spin them around several times then take them to one of the trees in the playing area. Allow the player to feel the tree for a minute, feeling it's bark, leaves and branches. Take the player away form the tree, spin them around several times. Take off their blindfold and let them have three chances to find the tree. If they fail they have to be blindfolded again and play until they get it right.
Source: From the original site.