Home-made steamer bags?
I love those disposable plastic bags with the steam-release holes you buy in the grocery store to steam vegetables in the microwave. But they are so expensive. Is there a way to make them at home that's (a) safe and (b) effective? Is there a viable substitute using a plastic container?
You can certainly steam in a Pyrex dish or measuring cup covered with Saran Wrap. The Pyrex safety instructions specify using a little water for frozen vegetables, rather than just assuming they contain enough water.
They sell all sorts of cooking solutions for the microwave from browning to steaming vegetables. I have a rice cooker I can use to make rice in the microwave....makes perfect rice everytime.
Any container that is microwave safe is a good substitute - see greygarious' reply. A cereal bowl, serving bowl, pyrex dish, rubbermaid container, glad or ziploc plastic containers, whatever. There is no need to buy special bags or plastic. And while you can cover with plastic wrap, a plate over the top of the container works equally as well. Save your money and use what you've already got in your kitchen.