From a "parallel" experience, here are my tips:
*Set your mind not only on remembering vocab, but on searching for them as well. It makes no sense to "read a lot" as teachers advise without a goal set in your head. But when you read with an eye for style, vocab, grammatical structures,...etc. even a little reading will be more fruitful than hours of absent-minded skimming of pages.
* Set aside a "beautiful" notebook as your mini-dictionary. You may divide it into sections as I do: vocab, idioms, quotes and proverbs. It is important to make it bright and beautiful so that you would enjoy revising.
* Revising your vacab may be the most tiring and boring of the whole process. Personally, I enjoy it, for one simple reason: this tiny, semmingly trivial step is my way to "master" the language! Indeed, it is a waste of time to keep stopping at the same word you have just looked up a day before! Besides, in the long run, your mind begins to think in English not translate from Arabic into English. I can tell you from my experience what a joy it is to find your mind assissting you with the exact word or a witty proverb at times of need. You cannot reap fruit you have not sown its seeds in the first place.
* Practice your vocab in the essays, compositions or any material you write. It also helps to play vocab games and do a lot of excercises. There are heaps of amazing sites on the internet. Just google them.
*One important and valuable way to improve your style in general, is to memorize whole sentences from the great masterpieces you read. You may then write by virtue of analogy or parallelism to these structures, thus refining your style rapidly.
*With extensive reading, revising, and practicing, you will find that you are sailing smoothly through the language sea-any language. Believe me, English is an enjoyable language, not as difficult as our teachers picture it. It just takes time, patience, and diligence. Keep working with these three, and -God Willing- you will succeed with flying colours.
Fragrant Regards