Use a metal sieve or colander that fits inside a large pot. Bring a few inches of water in the pot to boil. Place rinsed rice in the sieve lined with cheesecloth or a clean towel, set above the boiling water (not touching). Cover the pot tightly with foil and a towel to trap steam.
Steam for 20–30 minutes for white rice, longer for brown, checking water level occasionally.
This method gives gentle, even steam and works well when you lack a proper lid or rice cooker.