The Mountain in the Morning

We managed to avoid the rain on our morning walk. The air has been so clean and wonderful to breathe. In the afternoon, we also managed to avoid the rain, as he mowed the grass and I planted seedlings. But by about 5 it rained and rained and rained. It came down fast and furious, and then was done. My first thought as I awoke this morning was that we failed to capture and save any of that water. A person with a regular sized lot can only store so much water, so we usually don't bother, but what missed opportunity. I'd like to fashion a funnel in order to capture more rain water into a couple of old metal garbage cans we have in the back, you know, something much bigger in circumference to put on top of one of those cans to gather in more rain, then to be able to fold it up and keep out of the way. What should I make it from?