Taking the time to make small changes in your garden can actually have a large effect on the amount of wildlife that decides to stop by. For instance, by adding a few native plants that have scented flowers, berries, or seeds you can attract a great deal of butterflies, birds, and bees into your garden as well as other fascinating insects like ladybirds.
You also may want to consider pacing ‘food’ plants in various locations around your garden or create a border of fruit producing and flowering shrubs so that wildlife will be attracted to stop by on a more frequent basis. Even if you only have a window box consider tossing a few annuals with flowers in so that more butterflies and bees stop by your window sill.
Keep in mind also that while shrubs and flowers are quite useful when it comes to drawing in wildlife, wildflowers can also be very useful so allowing a small part of your garden to grow freely can also be beneficial in meeting your final goal.
If you have a larger garden, you may even consider choosing a range of plants that offer different food types during each part of the year so that you can enjoy wildlife in your garden year round. This will require you to plant during different times of the year as well, but the payoff will be well worth the effort.