I was inspired by a banner that a local kids store was selling. I liked the banner, but not the price: $45!
This one cost me close to nothing since it's mostly made from scraps and bias tape from an estate sale. So, my total cost was less than $5 (and I think I'm being conservative.
I first made a template of a triangle.
Then I folded my fabric and placed the short side of the triangle on the folded edge.
I cut out the triangle using pinking shears.
I cut out letters from felt and sewed them on one side of the triangle pennants.
Then I sewed the triangles over the bias tape. (I think twill tape or ribbon would work a bit better.)