ktbb

I usually use this technique and when you make the last seam off-setting the sides - it looks wrong, but it's right. I've tried cutting the strips with scissors and it works. However, I prefer to insert a small cutting mat inside the tube and cut with rotary and ruler.

If you need more than 5 yards of binding, you can always start with a larger square. One of the quilter's reference books (the turquoise and white one in the USA, I think) includes a chart telling you which size to start with for specific amounts of yardage.