A few years back, my husband and I agreed we needed a Christmas tree skirt. I bought a simple red felt one for 5 bucks. He bought a nicer red and green velvet-type one. We use his. The red one's been languishing in the bottom of a box of holiday decorations until recently - when I got the idea to make capes out of it. It took me 15 minutes to make 4 capes for the boys.
I began by cutting four equal wedges out of the tree skirt. You'll notice it has some decorative edging, but I didn't really mind that. I like felt because you don't have to worry about finishing edges. I knew there was a pretty good chance these would be destroyed in a couple of weeks, so I gathered some old ribbon from a gift we received some time ago. The ribbon's yellow with red writing that says "thank you." I figured that was appropriate for a super hero with all the rescuing they do. You can also add embellishments like initials or emblems, but I haven't gotten around to that yet.
I took the point of a cape and folded it over about 4-5 inches. I created a channel about 2 inches wide for the ribbon to slip through.
It is a great size, because it's not too long and it fans out... very cape-like.
Voila! Here's Tater modeling it...