The two main aspects of the TOEFL that prove to be of concern to students are the grammar and the vocabulary sections.
Grammar
Depending on how one classifies the various grammar items in the TOEFL test, there are approximately 46 different grammatical entities that you need to master. One of the major drawbacks of studying grammar merely by going through a TOEFL guide or two is that the student spends a lot of time doing questions that have already been mastered. My philosophy in this regard is to make up new quizzes that concentrate on the items that still need to be conquered. That is why I insist that students provide their email addresses in exchange for the answers.
Vocabulary
The essential ingredient in learning vocabulary that is missing in mastering grammar is the time element. The frustrating thing about vocabulary is that if the student learns, say 100 words before the test, there is every chance in the world that only five or six of those words will actually find their way onto that particular test. I have had students who have learned 500 words in three weeks and improved their TOEFL score to the extent that they never had to worry about doing the TOEFL again.
Strategies for mastering TOEFL vocabulary. First of all, a don't. Do not resort to taking down the target word in your first language. If you simply have to do that put it in a notebook that is kept for that purpose and only refer to it when it is absolutely essential. Recall is the essence of reinforcing vocabulary skills. Do crossword puzzles.
Essential TOEFL Vocabulary 1