I'm playing around a bit with 1 now. I've actually done a bit of 2 and I can tell you that the idea of growing enough calories to feed yourself is fairly daunting, which makes 3 a bit difficult (although I've had problems with that anyway I suppose).

Few more ideas:

Don't buy things you don't need and avoid products that don't last (i.e. break in a year or two). Try to repair a broken product first, before buying a new one.

Minimize commute & travel. Use public transport when you do.

Talk to other people how you did it, so that ideas can spread and norms change.

Little drops of water make an ocean.