A small yellow-edge prefold folded in thirds.
A small flat diaper, folded in half and then thirds.
You can use a snappi to fasten a prefold around your baby.
There’s a whole category of fitted diapers. Green Mountain Diapers (GMD) makes the most economical fitted – it’s simply one of their prefolds sewn in the shape of a fitted with a doubler tongue added. It’s called a Workhorse, and comes with or without snaps.
You can add extra absorbency into a diaper by stuffing it with doublers. Below is a pad folded cotton flat with a newborn size prefold.
Hemp is very absorbent, and this little doubler from GMD is so soft and thin. Hemp is slower to absorb than cotton, so it’s usually put at the bottom of the diaper, but wrapped inside something else is good, too.
You can even add fleece to the top to wick away moisture. The blue edge of these Malden Fleece Liners face baby.