Best Ways to Reuse Plastic?

[Squishie PP]

Depends on the type of plastic. Some are easy to melt down or dissolve, re-mold, and re-use.
If you are in the US, we have resin identification codes stamped onto all plastic items: https://en.wikipedia.org/wiki/Resin_identification_code
That will give you info on the specific material a plastic item is made out of.

 

[mold]

in what fucking universe would you be in the apocalypse, have a bottle, and think "I'm going to cut this bottle up into strips and turn it into something else"