Give each patient a blank piece of paper. Instruct the patients to draw the outline of a tree with whatever style of trunk they desire (You can instruct them to design it according to their personality i.e. Make a twisted trunk if they are a complicated person, or a straight branch if they are sure of themselves etc.). Then allow the patients to color in the trunk and branches of their tree. After they are done, allow patients to tear tine pieces of tissue paper of whatever colors they choose to create the leaves for their tree. Instruct the patients to glue the leaves on their tree.
*If you have a significantly low functioning patient, you can print out a picture of a tree, have them color it, and assist them in gluing on the tissue paper.