Eliminate the concept of waste. One of the ways in which I've been applying this is to stop doing sports. Sports are a way of wasting energy that doesn't get used in people's productive daily activities any more, because those daily activities all run on fossil fuels.
So I stopped doing sports; but apart from the fact that I'm not as young as I once was I'm possibly as fit as when I could walk 100 km in 24 hours. It's just that nowadays my energy goes into productive activities, mainly gardening, cycling and chopping wood. But the linking goes deeper. Rather than spending time in what I consider to be a soul-destroying gym, I spend my time on the lookout for toads while harvesting raspberries for breakfast and pulling out the nettles, wondering whether the field of unequal height wheat that I pass every day is inspired by the multi-variety approach pioneered by Martin Wolfe, and looking for edible mushrooms while collecting wood. Written down like that it doesn't sound like much, but then maybe that's the point.
This is not an advertising campaign to sell you the next fad that the biosphere doesn't have the resources to produce. This is about doing "less" with "more". Less unrenewable resource use, more skill, equality and connection. It's about the simplicity of growing your own fresh food from previous years' homegrown seeds.