When planting new trees or shrubs in your garden consider using native species, this will attract more wildlife.
Why not plant some hedges in your garden to provide your local wildlife with some shelter?
If you have a quiet place where you can put a pile of logs or twigs, your local wildlife will sure appreciate it.
Clear out any debris and weeds from ponds: leave them on the side for some time, so that wildlife has time to escape!
Do you let a part your garden grow without disturbing it? This may be particularly interesting: http://j.mp/OBvYfY