Many people have the impression that after time, birds will come to know you and might stand on your shoulder or your arm. This is certainly true of pet birds. Wild birds are a different matter, however. Pigeons are often seen as tame birds and this is evidenced by how comfortable they are around humans in urban settings. But pigeons are not true wild birds - they are feral domestic birds.
To the wild bird, you will be seen as a predator. You have all the characteristics of a predator - you're physically large, have unpredictable movements, and make noises which frighten them.
The best way to observe wild backyard or field birds is passively. This means keeping quiet and perfectly still. The best way to remain still is to be seated. Standing completely still for long periods of time can be tiring and will cause you shift around, creating movement and scaring away the birds. Bringing a small folding chair with you for observing birds will help in this regard.
Your goal is to blend with the surroundings as best you can. Aside from remaining still, you can further accomplish this by wearing neutral clothing - usually greens and tans, not bright colors like red and yellow.
After a few days in the same area, birds will become accustomed to your presence. It is only then that you can begin to make slow movements - such as raising your camera or binoculars. But remember, the wild birds will never totally accept you.
You should approach birdwatching as a privilege. By using this approach, you can appreciate the habitat of the wild birds in their natural settings.