I have always loved the tetra shape and I make all sort of things from it. This time it’s rice bags. I used some old fabric scraps that’s been lying around. All you need is a strip that’s twice as long as it is wide. Mine is about 12×24 cm. Fold it, rights facing each other, so it looks like a square. Sew along the two sides facing each other, leaving the third side open. Turn it right side out and fill it about half way full with rice. Fold in the edges and sew the last seem.