I can't tell you how many pairs of these I have made over the years. They're what I wear pretty much constantly for Spring and Summer, they're so comfy!
It's quicker with a sewing machine, but I've made countless pairs by hand. I even made a pair on a flight once, on the way to France!
I prefer to use cotton fabric for the outside: Denim is great, or a quilting weight cotton. Gingham, you can afford to be bold with the pattern if you'd like to! I've also used linen which works really well. Avoid anything too thick, synthetic or slippery. For the lining, I only ever use linen. It makes a huge difference as to how comfortable your shoes will be.
Here's what you will need:
Outer fabric - 1 x fat quarter (Cotton or linen)
Lining fabric - 1 x fat quarter (Linen)
Espadrille soles (and the pattern that comes with them)
Sewing machine or needle & thread
You must let me know if you make some, I'd love to see!