A few teen helpers came early to learn how to make the things, then demonstrated for the teen attendees. We got instructions from books* and from instructables.com. Our teen shelver took charge of the wallet activity. We've found in previous craft activities, that written instructions often get ignored, so we didn't bother with any this time. It saved me lots of prep time and worked well. Most of the activities are pretty easy to figure out from a sample. The wallet, cell phone caddy and roses were the only ones that really needed to be taught. It also helps that our attendees didn't seem to be perfectionists about their duct tape creations. The highlight of the event were the number of boys who attended - 5! We've also noticed that some of them are using their wallets!!!
*Books: Stick It!: 99 DIY Duct Tape Projects by Teresa Bonaddio, Got Tape? by Ellie Schiedermayer, and Ductigami: the Art of the Tape by Joe Wilson.