A tree is not the easiest shape to make a costume out of, but it can be done.
Whether it's for a Halloween costume or a production of, "The Wizard Of Oz," the need for tree costumes is one that occurs on a fairly regular basis. A simple tree costume is basic enough in shape, but to make a truly professional-looking costume requires a bit more finesse. Implement a few simple tricks for improving the shape of the smaller details of your costume as well as the larger essential pieces.
Branch Gloves
Transform real tree twigs into tree branch fingers. Cut 10 branches of about 5 inches in length, each roughly as thick as a pencil. Try to find branches that have a slight bend to them. Use flexible white glue to attach the branches to the tips of inexpensive knit gloves. When the glue dries, wrap each glove in brown yarn; do this by wearing each glove in turn on your secondary hand, coating it in glue, and wrapping from wrist to the tips of the sticks. This will give the gloves a consistent brown color and yarn texture.
Root Feet
For feet with a shape that suggests roots, give a pair of opaque, brown tights a divided, two-toe shape. Machine sew a "V" shape up the middle of each toe using a tight cross stitch. Position the base of the "V" at the edge of the toe and make it measure about an inch and a half at the base and 2 inches high before the hose are stretched. Put stuffing in the toes to fill out the shape. This works best if the tights are a size too big for the person wearing them.
Branch Hat
Use your headgear to imitate foliage. Start with a hard foam bicycle helmet and spray paint it green. Either purchase artificial tree branch twigs (found with floral supplies) or gather some short tree branches. Get sections with lots of leaves, but no branches thicker than a pencil, or it'll be too heavy. Spray real branches with shellac varnish to preserve them. Use an oscillating power tool to cut small holes in the bicycle helmet and glue the stems of the branch in place with wood glue. Attach as many leafy branches to the helmet as you can.
Makeup
Makeup is an oft-neglected part of tree costumes that will make a big difference in how the finished product looks. Apply at least a base coat of brown or green stage makeup to cover your face, depending on whether there are more green or brown portions of the costume near your head. If you like, paint your face with overlaid leaf patterns or wood knotwork to make things extra fancy. Finish off the makeup with a light dusting of translucent makeup powder to help keep the makeup from smearing and running.