Infinity dresses are a great staple to have in your closet. They take a bit of fabric, but they can be made in under an hour and can be wrapped so many different ways that it can look like a million different dresses!
For mine, I used an abstract cloud printed neoprene from Mood, which was absolutely beautiful, and reminded me of being on a plane at sunrise. Fashion-weight neoprene also has a fantastic drape and really lends itself well to circle and skater skirts.
The pattern for an infinity dress is beyond simple. All you need is a circle for the skirt. The opening in the middle should be about 3" less than your waist, since neoprene is a stretchy knit fabric.
For my waistband, I cut one continuous strip, 8" high, and folded it over with a seam in the back. I don't recommend this, since there are many ways you can wear the dress backwards, and the seam could often show. Instead, cut 2 waistband pieces for two side seams. The height could also be easily altered. 8" high, folded over, would of course give your a thick 4" band. Some people like to make theirs even higher to fit over the bust.
The straps are equally simple. They should be 1.5 times your height to give them the length to wrap around your body several times. You can make yours 8" wide and sew them flat to the skirt, or you can double that and gather them as you attach them.
As for the sewing, there are only three steps!
Once you're done sewing, start experimenting with ways to wrap it - there are literally endless possibilities! Let us know in the comments which fabrics you'll be using and how many styles you can think of!