For your referee pants, simply use a pair of comfy black sweat pants.

In order to get the right amount of material, use a well fitting long sleeved shirt and take it with you to the fabric store. This shirt will be your "pattern". Find some black and white striped fabric you love and have them cut enough for you to make a front and back of the shirt.

Simply fold your fabric in half and lay your child's shirt on top of the folded fabric. Cut out the shape of the shirt an extra inch all the way around the outside of the shirt.

To make it super simply, you don't have to sew the neck, simply cut a circle for the head, then cut a slit down the back of the shirt - big enough to allow your child's head in.

Don't be scared - sew from the end of the sleeve, up to the arm pit, then down the side. Repeat for the other side of the shirt. You're done. You can hem and do other fancy stuff like that, but it isn't necessary.

For the hat, I just bought a black hat from Amazon and hot glued the white embroidery thread along the seams of the top of the cap - just like a referee.

I also bought an iron on American flag patch and put it on the front of the costume - again, totally optional.