Rinse the 1 cup of glutinous rice until the water runs clear (4-5 times).
Pour rice into a bowl with 2 cups of water. Let soak for 4 hours or overnight.
Prep a steamer by bringing water to a simmer and add the steamer insert. Place a sheet of parchment paper or cheese cloth on top of the steamer insert.
Steam for 40 minutes.
Taste the rice for doneness. If it is undercooked, keep steaming for a few more minutes before testing again.
Notes
If you want to use a rice cooker, I would recommend using a rice cooker with a steamer basket and steaming the rice in the steamer basket.
Another thing you could do is test the sticky rice a few times in your rice cooker, so you know the exact ratio of rice to water. There are also nicer rice cookers with a sticky rice/sweet rice option in their settings which means it can cook sticky rice accurately. I would generally recommend a 1:1 ratio to start for sticky rice cooked in a rice cooker. Test out a batch and adjust accordingly. Add more water if the rice seems too dry or less if it seems too mushy.