This trick-or-treat costume will put you in sync with a '60s vibe.
Wig: See the basic wig instructions. Use two skeins of a straight, medium-weight yarn to make a wig with hair about 25 inches long. Make one bundle with 22 strands of yarn and bind this thicker bundle onto the cap first. The rest of the bundles can have 18 strands.
Vest: Cut a brown paper bag as shown. Have your child try on the vest and make any alterations as needed. (If the shoulder straps are too high or straight, cut through them, overlap the ends, and use double-sided tape to reattach them. Do the same to bring in the sides of the vest, if needed.) Turn the vest inside out so that any printing is hidden inside. Line the edges inside the vest with packing tape to prevent tears. Use double-sided tape to tack down any loose flaps.
For the fringe, cut the bottom 16 inches or so from the T-shirt, then cut this tube open into a rectangle. Tape the fabric to the inside bottom of the vest, then cut it into skinny fringe. Make flower power pins from cardboard and attach them to the vest with double-sided tape.
To complete the costume, add a tie-dyed T-shirt, round tinted glasses, a peace-symbol necklace, and a counterculture headband made from an old tie.