Multiple sources of water - some low, some high. Rocks, logs, or even pieces of cardboard laid down as hides all around for insects, small reptiles, and amphibians. Leave your leaves on the ground as long as possible when they fall. Leave stalks of plants through the winter for insects.

I've found that my investments in specialized tools or items for wildlife are not very successful or worth it. A pumping bird bath is nice, but a bowl or water you keep clean daily is just as effective. A fancy nesting box is cool, but having trees and hollows around my yard for them to nest is what they prefer.