Dear Waqas,
I have studied English from Sir Bukhari and i think he is a good teacher to get assistance for precis and composition. He improves vocabulary, grammar, sentence correction, voices, direct-indirect tenses, idioms etc. But as far as 'Essay' paper is concerned, you have to work on your own or look for another teacher. He doesn't really give heed to it. He only checks essay and tells the student about the mistakes he had made in it but doesn't give directions on how to attempt and structure of the essay. On the whole he is a very sound English professor with a lot of experience under his belt.