Here's how I made the horns:
Cut the noodle to length:
Cut off the end at an angle:
Use tape to anchor the ribbon or twine to the noodle. You're going to be winding this pretty tight, anchor it well.
The cut/tapered end will become round in this step:
To make the curve, bend the noodle and put a piece of tape along the underside of the curve. Then tape over it. Three times.
It doesn't matter how long the pieces of tape are. It all blends and the horns are supposed to be textured anyway.
For the end, add a little extra tape:
And twist it:
Now do it all again for the 2nd horn:
Hot glue the horns in place on the headband:
Warning: Industrial hot glue guns melt pool noodles. Learn from my fail.
Add tape to the base of the horns, around the headband to secure them in place:
All things are possible with time and duct tape:
I'll see if I can get the girl to model the complete costume later.
These horns are light weight and sturdy. And quick and cheap. I think I spent $3 getting supplies that I didn't already have around, and total time was less than an hour.