I am not a great fan of plastic.
I mean, I like the qualities of plastic: that it's unbreakable (or, at least, shatterproof), durable, watertight. Lightweight. It's a great idea. But I don't like that it's made from a non-renewable resource (crude oil, ultimately), and is rather tricky to recycle. It's not great at rotting, tending to stick around for ages, clogging up the place for hundreds of years.
So wherever possible, I prefer to avoid plastic, and choose alternatives that are made from renewable materials, or can be more easily disposed of at the end of their life, through recycling or bio-degrading, or composting.
I eschew plastic bags, choosing instead to use my hands and pockets, or cardboard boxes.
I buy my milk in glass bottles (that, as well as being made from the wonderfully renewable glass, are rinsed, returned and reused). I buy baskets and wooden storage boxes. I have a metal toolbox I inherited from my father (and might yet pass on to my son).
There are, though, times when only plastic will do. To store something in a sometimes-damp garage, safe from rodent's teeth, protected from the weather - plastic is pretty much the best choice.
In these cases, I choose plastic that is durable, robust, and - if possible - made from a type of plastic that can be recycled (or, at least, downcycled). And I plan to keep it for a long time; I weigh my current needs, my future plans, and choose the best fit that will last. If I'm going to buy plastic, I want it to be as infrequently as possible, and I don't want to be throwing it away any time soon.
Getting the best - the most - out of what I spend my time and money on. That's my kind of environmentalism.