I make my kids have costumes that go together every Halloween.  Last year they were Dorothy and the Scarecrow.  The year before Princess Lea and Luke Skywalker.  (I will share pictures sometime).  Denali and Dylan are a shark and a scuba diver this year for Halloween.  This is their father’s fault, he has forced them to watch too many nature films and Discovery Channel.  My husband is a High School teacher, and pretty much a science geek.  Denali’s Scuba Diver costume was relatively easy to make.  I made the tanks out of 2 liter soda bottles spray painted silver.  I also made her a weight belt with wide elastic and a couple snaps in the font.  Dylan’s shark was a different story.  I could not, for the life of my find, a pattern for a shark.  Potterybarn had a cute shark costume for around $60 (couldn’t afford that) and Old Navy had a toddler sized shark.  So, I used pictures from Potterybarn and borrowed my friend’s son’s Old Navy costume and came up with Dylan’s costume.  He was adamant about the shark being mean, I hope I achieved that.  They look super cute together.  I have to make my kids costumes, my mom always made us fantastic costumes (it’s a family tradition).