Not lining a bamboo steamer basket
Bamboo steamer baskets are a tried-and-true method of steaming food. They work well with dumplings, vegetables, and everything in between. Remember to line the bottom of the bamboo steamer. Because of the nature of the bamboo material, food sticks to it very easily. Furthermore, the bamboo basket may absorb the scent of whatever you steam in it (especially fish), so it's critical to create a barrier there. Because lettuce and cabbage are porous by nature, they can be used as natural liners.
Other inventive liners, such as corn husks or grape leaves, can be used to add flavor to the food you're steaming. If you use parchment paper as a lining, make sure there are holes in it to allow the steam to reach the food. Fortunately, steamer liners (similar to those used in an air fryer) with pre-drilled holes are available.