These work best in a lighter fabric with relatively good drape.
A light cotton, or chambray are particularly well-suited.
Rayon or jersey will work too, but will give it a more casual-look.
For the opposite effect, less casual and more style, you can consider a silk blend or light wool.
Resist the temptation to make these in linen. While linen is the go-to for hot summer days, I would not recommend it for these pants as they come with an elasticated waist/cuffs, which means wrinkle hell. Use one of out other designs with a fitted waist if you want linen pants.
Also avoid picking a fabric with a lot of stretch, for it will complicate matters when you’re installing the elastic.