To be self sufficient (or striving to be as much as possible) we not only grow the garden and keep livestock.
We also strive to "recycle" as much as possible - not just by sorting our garbage.
When starting up living self sufficient, we also started to consider, what we could use for other purposes, than just filling up the garbage can.
Emty plastic containers from storebought food, marmelade, ice cream etc. is cleaned and used again for food that goes into the freezer, fridge, as lunch boxes (and for leftovers for the son who just moved away from home :-) )