There may be one right way to steam food (see Vegetables, Perfectly Steamed & Sauced), but there are many types of steaming inserts you can use:
A folding steamer basket is inexpensive and versatile
These inserts are best for small amounts of food, but they fit in just about any size pot. Nestle one into a deep saucepan or spread the steamer’s leaves wide in a skillet. The one in the photo sells for about $7 at supermarkets.
Asparagus steamers aren’t just for asparagus
You can cook lots of asparagus in the tall metal basket, but you can also use it for other lengthy or bulky vegetables such as corn on the cob and artichokes. The model in the photo is $34.95 at surlatable.com.
Bamboo steamers are stackable and pretty
Stack these drum-shaped steamers two or three tiers high to steam a lot at once, including foods that have different cooking times. They were originally designed to be used in a wok, but you can also set them over a stockpot. A 10-inch, two-tier bamboo steamer is $14.99 at fantes.com.
Non-collapsible metal steamers are durable and roomy
These perforated steamers come in a variety of sizes and shapes; some even have stackable tiers for more capacity. The stainless steel insert above is $35 at surlatable.com.