Start at the top. Look at the top of the bird’s head, and then move your gaze toward the tail. Key identifying features of a bird’s plumage and appearance are called field marks. Most birds have two or three field marks (a crested head, black wings, a long bill, or a striped breast, for example). Noting these very obvious field marks will help you identify almost any mystery bird.
Look at the bird, not the book. Although it’s tempting to take a quick look at a mystery bird and then dive into your field guide to find its matching image, resist this urge. Birds have wings, of course, and use them often to take flight, so watch for as long as you can before reaching for your guide. While observing, try to obtain a general impression of the bird’s size. Field guides aren’t usually organized by size, but knowing how big or small the bird is helps to eliminate choices.
Notice behavior; listen for sounds. The bird’s actions and sounds can be helpful identifiers. A bird hammering on a tree trunk is likely a woodpecker; a large bird soaring high in the sky might be a hawk or vulture; and a low-toned hooting emanating from the woods at night is almost certainly an owl.
Consult the field guide. If you think you know what general family your bird belongs to, use your guide’s index to turn quickly to that section (most are divided by water or land habitats). If all else fails, flip through the guide’s pages looking for similar species. Over time you’ll know general families to which birds belong, and your searching will be more focused and fruitful.