First and last light
When photographing garden birds, the direction and quality of light, and the background, are key to making great images. By working out how the light falls in your garden, you will be able to set up perches so that they are illuminated at the times during the day when the birds are most active. I prefer to shoot at first or last light, or during overcast but bright conditions, when the sky acts like a giant softbox, reducing contrast. Place perches far enough in front of any background vegetation so that the background is rendered out of focus.