Plastic is great! It’s a great material, I love it for e.g. skiing helmet, protective devices for sports, medical devices, we need it for many things.
However, for other purposes – like single-use plastic packaging – it’s totally stupid to produce stuff made out of plastics.
My kids did something funny some time ago: My then 11 and 8 year old started this on their own: They started to walk around in our flat searching for items made out of plastics. And then they always discussed whether there is an alternative solution which is made out of another material (if yes which one) or if it’s not necessary at all.
Could be a fun exercise also for other families?

Also nice for smaller kids who can then learn something about different materials around them: Touch different materials and discuss their use and environmental impact. 

And also how these materials affect you: Do you like them or not?

Try to let go the items which you do not like, the items which do not make you happy.

Replace broken items which are made out of plastic by higher quality material items (or decide that you don’t need them at all?)