To start off, you will need the following: an elastic headband, at least 8 yards of tulle, some ribbon and other embellishments (I've seen ones with pom poms glued to them), scissors, and a pattern (there are ways to enlarge the one I used, I'm sure, but I just drew mine free-hand). A few pins might be helpful too. By the way, that ruler is two feet long, by 16 inches wide. So the pattern is approximately 9.5 inches wide by 14 inches long.
To start, fold the tulle in such a way as to not waste much fabric. I have no idea how mine was folded. We just kept folding until it was a nice size. The pattern will have to be flipped over halfway through, unless you want to cut through double the layers of tulle. I don't have a picture pre-cutting, but I do have one post-cutting. After the fabric is cut, very carefully take four layers of tulle at a time and loop around the headband, like so: Then pull it somewhat tight, but not too tight, as this tends to stretch the headband out, and then it's too loose to fit around your little girls waist (unless she has a waistline like an adult). Continue to loop until you are out of tulle. I used seven yards (one more yard would have been nice) and ended up with 14 sections. Eight of one color (four yards) and six of the other color (three yards). The pattern I "borrowed" this idea from used somewhere around 11 yards, and was very full. I think this one turned out quite full enough though.
Once all your tulle is attached to the head band, add ribbons, etc. I tied the ends on each of my ribbons, so they wouldn't fray too bad, then looped them around the head band the same way I looped the tulle. All in all, this took maybe an hour to do. I accidentally bought the expensive tulle (although I used a 40% off coupon), so the price came out around $10. A little bit more than I had hoped for, but I did buy three yards of fancy beaded ribbon which was a dollar a yard, at the Dollar Tree. If you have lots of ribbon lying around you will save some money. I did have the silver and plain white already. If you used wired ribbon, pull the wire out beforehand, so you don't have to worry about it scratching a child. Although you can probably buy a tutu for cheaper at the store, this one is so much cuter, and tailored to your child's personality. My daughter loves the blue, and I do too. But pink, purple, yellow, orange, red, etc...all would be way cute. Usually you can only find pink tutus at the store, and I don't do pink.