I haven't been able to blog about this yet as it was a present for my mum who is a reader (possibly my only reader!) but now I've given it to her I can share it with the wider world!
It's very easy to do. Zig-zag stitch the triangles and cut them out after, I find this makes it easier to machine sew because you have more material to hold. Do as many triangles as you like! The more the better I think.
Experiment with the order you like the best by laying them next to each other.
The finishing touch it to sew bias binding to the tops of the triangles, and sew the ends into loops for hanging. Voila, beautiful bunting, and at a fraction of the price in some stores, even though bunting is probably worth every penny.