Cooking in a bamboo steamer. Soak the sticky rice in water for at least 4 hours (preferably 6 hours to overnight).
When it's ready to cook, add 4 cups of water in a wok or pot and bring it to a boil. Meanwhile, line a piece of damp kitchen towel in a bamboo steamer.
Drain the presoaked rice before spreading it out evenly on the towel. Poke some holes in the rice to allow the hot air to flow through. Fold in the edge of the towel before covering with lid.
Set the steamer on top of the pot and steam for 25-30 minutes over medium heat. If the rice is not cooked through, sprinkle some water, turn and flip the rice a bit and cook for another 5 - 10 minutes.
Cooking in a rice cooker. (this method doesn't work with an Instant Pot)
Rinse and drain sticky rice very well with a strainer (no need to pre soak) before putting in the rice cooker pot along with 1⅓ cup of water. Cook it the same way that you'd cook white rice. Once it's done cooking, fluff the rice with rice paddle/spatula right away to loosen the rice.