The 6th Permaculture principle is "Produce No Waste" (you can see discussion of the first 5 Principles here).

This principle can be justified by observing how nature deals with leaf litter, dead animals, and other "waste" that accumulates on the surface. Eventually decomposers break down these items and incorporate them into the soil where they add fertility and nutrients to the soil. Nature produces no waste. The output of one process or event is consumed by another process or event.

David Holmgren, who defined and discussed these principles in his book, Permaculture: Principles & Pathways Beyond Sustainability, talks about the 5 main ways we can produce less waste, namely, by observing the 5 R's: Refuse, Reduce, Reuse, Repair, & Recycle. For example, refusing to purchase or consume an item is one way to produce less waste. David has adopted a lifestyle of voluntary frugality so refusal may be his main line of defense in producing no waste. When David discusses the principle of reuse he lists off the many uses we might have for our waste stream, e.g., for bottles, bags, plastic vegetable trays, milk containers and so on. Because David purchases so little from stores (supplying most of his own food) he has to ask other people for these items because he has uses for them on his property (e.g., bottles for home made beer, bags for storing things, vegetable trays for organizing nuts and stuff, milk containers for transplants and to protect plants).

Each waste reduction strategy is discussed in some detail in his book. David points out that while the "recycling" strategy gets most of the attention, it is actually one of the least useful strategies because it often requires significant inputs of energy to recycle an item whereas the other strategies don't incur this cost as much.

David also mentions the concept of "hierarchies of best next use" as a way to think about stuff for the purposes of reusing it. Here is an example that David uses to illustrate the idea:

In addition to discussing the 5 R's as strategies to reduce waste, David also discusses the importance of durability and maintenance in reducing the waste we generate.

The co-founder of Permaculture, Bill Mollison, defines waste as "an output of any system component that is not being used productively by any other component of the system". For Bill, the problem of waste is the problem of not being able to imagine a productive use for a system component output. The "produce no waste" imperative requires us to regard waste as a problem of the imagination and that we look for solutions that consist of using any waste stream as an input that can be used to increase the productivity of another system component. See the wikipedia entry on Life-cycle Assessement for some current ideas on how the "produce no waste" principle is being used in manufacturing. An important book in green manufacturing is the 2002 book by McDonough & Braungart called "Cradle to Cradle".

Overall David's chapter on the "Produce No Waste" principle is useful because it discusses some of the main strategies that can be used to eliminate and reduce waste as well as the Mollisonian mindset we could adopt when tasked with the problem of dealing with waste in its many forms (e.g., plastics, organics, weeds, stormwater, sewage, etc...).