Experience of being a tutor

I am now being a tutor of a senior high school student. He is a boy who is good at math and science but has poor English ability, especially in English composition. He can read an article and understand most part of it but he can not write down what he thinks clearly. Briefly speaking, he has difficulties in English writing. To improve his English, we started from improving his grammar. We read a grammar book thoroughly and make practice. And then, I wanted him to memorize some sentence patterns and proverbs. Both of those may provide him of some food of thought when writing an article. By following these tips, I think he will certainly get a better grade than before.