Give your child an out-of-this-world Halloween by creating a homemade alien costume. You can stick with the basics and make a traditional green Martian, or let your imagination run wild and create an alien the likes of which has never been seen. Even if Halloween is still a long ways off, you can still make an alien costume for your child to wear to a theme party or simply while playing.
Measure from your child's shoulders to his ankles. Also, measure the width across his shoulders and the circumference of his head.
Cut the fabric so it is twice as long as the length from your child's shoulders to ankles and one and a half times as wide as his shoulders. For instance, if he is 40 inches from shoulder to ankle and 14 inches shoulder to shoulder, cut a rectangle of fabric that measure 80 inches by 21 inches.
Fold the fabric in half width-wise. Cut a hole in the middle of the fold big enough for his head to fit through.
Cut a length of cording or ribbon that fits around the hole you cut for his head. Pin the cording or ribbon along the edge of the hole. Hand sew the ribbon to the fabric.
Fold the edges of the fabric under about 1/2 inch and pin. Sew along the edges to hem.
Cut the black fabric into a fun shape or letter to make an emblem for the chest of the outfit. You can cut an "A" for alien or get a bit more creative. Pin the fabric to the front of the metallic fabric and hand sew in place.
Paint the foam balls with the metallic or glitter paint. Paint the swim cap green, or whatever colour you wish. Let dry for a few hours or overnight.
Carefully poke two holes in the top of the swim cap. Twist one end of each pipe cleaner and thread the through holes for antennae. Push the foam balls onto the ends of the pipe cleaners that stick out.
Line the swim cap with batting to give your child's head an enlarged look.
Put the unitard and knees socks on your child. Pull the metallic fabric gown over his head. Wrap the belt around his waist to secure the gown.
Drape a towel across his shoulders to protect his costume as you apply the alien face.
Pull the swim cap over his head. Apply a line of spirit gum to the front edge of the cap to hold it against his forehead. Shape the putty into a line and use the gum to attach to his face to form ridges. You can place the putty down his nose or across his forehead. Shape it into triangles and attach to his ears if you would like.
Paint his face green, grey or any colour you'd like to conceal the putty and give him an alien look. Use black paint around the eyes to give him large, alien eyes.