Most gardeners will focus on growing food. But while growing your own food is obviously a great strategy for sustainable living, it is also useful to think about the other non-food yields you can derive from your garden.
The first category of non-food resources to consider are plants which can be used to reduce or eliminate your reliance on household cleaners.
There are a number of natural "soap plants" which you can grow to create a natural soap. Soapwort and clematis are two that grow where I live. And amolla and yucca are two other plants to consider. Many other plants which are high in saponins can also be useful.
I make apple cider vinegar from apples from my forest garden, and also use this regularly in my cleaning routine.
While I do not have the space to grow crops to yield oils for soap making. I can generate lye from wood ash, some of which come from trees grown on my property. I also grow a range of herbs and flowers for use in soaps and other cleaning and beauty products. Lavender, rosemary, thyme, mint... and many more.
And these are just a few examples of the uses of plants that you can grow in your garden for bathing, skin care, hair care, etc.
There are also plenty of other things for your home that you can make from the plants in your garden. One rather obvious example is that where the land is available, you can grow fuel for a wood burner or stove.
You could grow willow or other coppice trees for basketry and many other crafts, make your own natural dyes, and even make fabric from plant fibers such as flax or stinging nettles. And these are just a few examples.
You can also grow many medicinal herbs and other medicinal plants, which can help you to take care of the health of you and your family. You can make tonics, teas and other preparations to use plants from your garden to stay well.
And you can beautify your home, not just your garden, by cutting/drying flowers to display indoors and to use in a range of crafts. Seeds, leaves, and many other plant ingredients can also be used in home decoration and crafts.
I use nettles to make string/twine for garden use. And plan to do more with nettle fibers in the future. And there are plenty of other resources for the garden that I grow on-site to create closed-loop systems.
Of course, I compost organic materials to return nutrients to the system. And I make organic mulches, use chop and drop plants and make liquid plant feeds. Some plants (most notably, comfrey) are grown largely for this purpose, as good, fast-growing sources of biomass.
I also use branches, twigs, and other natural woody materials from my garden in a huge range of different ways. From building new growing areas to making plant supports, to making fences, bed edging, and more. I also chip woody material and use it to make paths through portions of my garden.
Those there are plenty of other ideas to explore, the above should begin to show you how a garden can allow you to grow far more than just food. The more you grow, the more options you will discover to make the most of all the resources the plants in your garden can provide.