Thanks Interview, Nikol, Webhead, Danko75 and Freewaldo
@danko75: You need to draw faces a lot, portraits etc. It will train your eyes. And yeah your right about observation and patience. More you sculpt more you learn. It will be hell frustrating in the start, but its a phase.
People get easily afraid and this point and leaves it. So Dont QUIT , keep learning and show your progress to other and take feedbacks.
**Also one tip, when it comes to likeness , take breaks in between. It will help you give fresh perspective when you see after some time and you can easily see what is working out and what is not.