Trial and error is the best way to learn.
Exactly what it is that you want to say with your photographs? For landscapes, my photos are just to show the beauty of a scene. I try my best to bring that out through good composition and colours. As for portraits, I wait till people are their normal selves and they decide which part of their personality they want to show me.
Did you get to work with ad agencies on specific assignments? If so can you speak of one such project? If not would you like to shoot for advertising campaigns? I would love to shoot a documentary about the inner working of Etisalat and I am waiting for the right chance to do so.