Prepare a journal and carry the same with you wherever you go. If you spot a bird, draw the sketch and mark different parts such as the eyes, head curve, beak, feathers, tail, color patterns, flying style, feeding styles, overall size, estimated weight etc. These sketches can later be used to compare what you have in your field guide or confirm with local birders. Bird spotting can get very tedious, so be patient and make sure your notes are properly organized. Along with the basic physical characteristics of the bird, mark the date and time of spotting, the location and weather and the natural habitat. Also, mark their abilities such as ability to swim, flight distances, wing movement, chirping sounds or other sounds they make. Your journal would hold information on different kinds and species of birds that you have seen so ensure that you are noting everything in detail.
The final step would be to get hold of bird pictures and charts. Compare what you have with the field guide carefully, don't just settle down with common matches, but make sure that you confirm the match by doing deep analysis and if the need be take help of local birders.
Identifying birds can get very annoying without having the right set of guides with you. Sometimes there are so many similarities that you may easily be bogged down, but start slowly, spend adequate time on each bird and have as much information as you can in your journal. If it is possible always use pencil to make the final markings in your journal so you won't have to go through the pain of erasing and scratching if something goes wrong.