It's easy to make a Bow Tie! There is some hand sewing involved but it's so fun! You don't really need interfacing but if you want the bow to be very plump, use some lightweight interfacing.
For an adult male, cut the neck strap 19 by 3 inches. For a child it only need to be 15 inches long.
Cut the center piece 4 by 4.
Cut the Bow piece 11 by 7 for an adult and 10 by 6 1/2 for a child.
Use matching thread for the center piece because that will show.
Use a thin velcro strip that can overlap if necessary for the closure.
Here's a link with instructional photos:
http://charmedbyashley.com/childs-bow-tie/