Avoid using harmful chemicals or feeds around the area such as weed killers or slug pellets. There are less harmful alternatives incorporating natural organisms such as nematodes into the environment to combat pests and ferrous based slug pellets are available which aren't harmful to wildlife in the food chain and prove safer for pets and children also. Good old elbow grease is often the key to efficient weed control!
Use Peat free compost to help preserve the wider natural environment where peat bogs must be maintained as a storage system for Carbon Dioxide in the air, important in combating climate change.
Try making your own compost, it's easy! Composters are fairly inexpensive and often sold cheaply by local councils. Always place on the earth and layer your garden waste inside ie Grass (nitrogen source), Paper, Cardboard, Woody cuttings (carbon source), this provides the perfect mix for successful compost. Please don't include too much kitchen waste ie vegetable peelings, as in my experience it can attract vermin which isn't desirable.
Save water in your garden by creating storage systems from re-cycled plastic containers which you can obtain from websites such as freegle or freecycle, it's much cheaper than buying a water butt. You can then keep your garden, water features and wildlife hydration stations topped up.
Make sure you select plants and seeds that are classed as native species not continental as invasive varieties have previously been introduced into both the countryside and gardens to great cost in their clearance and the loss of native wildlife habitats.
Try to buy wooden fencing and garden furniture which is sourced sustainably and has an FSC guarantee, otherwise recycle some and give it a new lease of life!
All these things will serve to help the environment, preserve wildlife and biodiversity not just in your area but around the world!