Tops

• Start with tie-dye. Take a child's-sized white T-shirt that they don't wear often, or buy a new basic T-shirt. Using fabric-safe dye and rubber bands, tie-dye the shirt in as many or as few colors as you or the child would like. The tie-dyed shirt is a perfect base for the costume. It can stand alone or you can add a fringed vest or poncho over it.
  
  

Bottoms

• Bell bottoms are essential for a male or female costume, as they were a fashion staple of the 60s. Remember that bell bottoms are not a slight flare of the pant leg, but an exaggerated flare. Denim or corduroy bell bottoms are suitable for such a costume. If you cannot find a pair that would fit a child, consider taking a pair of child-size jeans and cutting the seams at either side of the pant leg, from the knee down. Add a large triangle of flowered or psychedelic-patterned fabric between the cuts to create a large flare. You can secure the fabric in place by sewing it, or if you don't mind a few rough edges, stapling it in place.
  
  If the hippie costume is for a girl, a large, flowered, peasant-style skirt is very appropriate and should be easy to find at thrift stores or vintage clothing stores. Even if you can't procure one small enough for a child, an adult-sized one can easily be cut and tied to fit a child.
  
  

Accessories

• If the child who will be wearing the costume has long hair, that's perfect. Have them wear their hair down and add a beaded headband that wraps around the skull, covering the forehead. If the child doesn't have long hair, consider adding a long wig to the costume.
  
  A peace-sign necklace is a classic addition to a hippie costume. Long beaded necklaces can also be added. John Lennon sunglasses are an important accessory as well.
  
  If you can find a sew-on patch that shows a piece sign or says "Flower Power" or something against war, it would be a perfect addition. Keep in mind that many hippies were politically active and against violence.