If you want to do it cheap and easy, I've taken and laid my kids arrows out, usually three, side by side. I'll have them on top of some heavy brown paper like a grocery sack.
Then I'll draw a straight line down one side and put a hook on the bottom like this: J. Then mark the center and cut out the paper along the first line and then fold the paper along the center line. Then you end up with a pattern that is kind of like putting a J and a backwards J together. Get the idea?
Then before sewing it shut along one side with some artificial sinew or doing a whip stitch around it with some 1/8" leather lacing I'll attach the shoulder strap to the bottom of the quiver. Once the quiver is sewn up I'll adjust the strap and attach it at the top.
Cheap and easy way to build one! Of course down sizing the one in the link above would work too.
K.C.