I just made my first woven headband lately too and love it! So cute and fun! I think I may have found a new obsession. Haha!
I'm not much help since I've just started, but I'm too cheap to actually BUY instructions, so I'll have to figure it out myself by looking at pictures.
I know to do the stripes, you just weave the same way. Only use two colors, two strands of each. At the beginning when you glue the pieces in an X shape, glue the same color to eachother. Or I guess you could just use 2 yards of 2 colors and glue them together in the center to form an X.
That was probably pretty confusing. If I get to making a striped one soon, I'll take some pictures for you.