More about how to review classes.
When your speaking class is over,
1) forget about whether you can “understand” the lecture or not; focus more on speaking. Simply put, you can read the script of the lecture and practice responding.
2) Once you say it again, you sit in front of the computer (which you usually do when you study for the TOEFL) and type out what you have said word by word. Then count how many words you uttered to see if your speech is sufficient in content. A rough estimate is that if you utter 90 words for Q1 and Q2, and 120 words for Q3~Q6, you will get the full score of 4.
(There is no need to see if your speech is grammatically erroneous. Nobody counts your mistakes…even in the TOEFL test.)
3) If your speech is short, think of how to fill the gap without repeating the same sentences. This is when your “speaking ability” is improving. The lack of this practice will allow you to make excuses not to have anything else to talk about.
4) When your final response is made, save it on the PC and read it aloud from time to time until you get the knack of it.
As far as the writing class is concerned, there is virtually nothing else to do but learn what you got as a sample response. Unlike the reading class, you should read this aloud (it is just 300 words long, after all).
1) how to develop your opinion
2) how to show examples
3) how to refute an opposing idea
4) word choice
5) grammar points already familiar to you but hard to use
6) other phrases that make a difference
Learn all of the above until you become confident you can reproduce the entire essay from scratch. This sort of input cannot be ignored if you are to succeed in writing. People tend to write more in order to write better. However, the most important is to read more. Read what you are supposed to write and learn how you can make it.