Beth Katcher, Patriots Trail Girl Scout Council, Boston, Massachusetts:
Hold the straws in a row, with the yarn tied to the bottom straw. Begin weaving the yarn over and under the straws. When you reach the top, just loop around the top straw and repeat the under/over back to the bottom straw. Just keep doing this, moving away from the end of the straw with the yarn until the woven part is covering all of the length of the straws. Gently push most (but not all!) of the woven part onto the lengths of yarn hanging from the straw and continue. Continue weaving until the loose pieces of yarn are almost completely filled.
Gently push the work off the straws, cutting the yarn where it was folded through the straws. Make sure you don't accidentally push the weaving off the yarn! Tie off the loose ends.
You can cut the yarn and swap colors at any time to make stripes.
Joi Ball, Girl Scout Council Colonial Coast, Virginia: I did Soda Straw Weaving with my Brownies and at Day Camp. We were a bit different than you...
We only used 3 straws, and held the straws vertical (straws up and down, extra yarn hanging out of bottoms). We had one yarn per straw, not doubled. Each straw had a short slit cut long-ways in the top edge.
To get the yarn through the straw -- push the end of the yarn into the straw a little ways (won't go very far..yarn is so flimsy), then suck on the end of the straw like you were thirsty. The yarn will fly through the straw and every girl with go Phew!!when they get a mouth full of yarn. Anchor the end of the yarn in the slit in the straw.
Weave as Beth said, pushing woven 'material' down off straws onto the strings hanging from the straws, until strings are full. Make belts, bracelets, hatbands.