You will have to decide whether or not you are going to teach yourself the TOEIC with reliable resources or whether you are going to take a TOEIC preparation class. In order to get the best results, you should do both. If you cannot afford to take a TOEIC class, make sure to choose a TOEIC textbook that has explanatory answers. You will also want to have a teacher or tutor that you can go to from time to time with questions.
If you choose a TOEIC class, make sure that you trust your teacher and feel comfortable in his or her class. Take a class with a friend and make a commitment to study together in and outside of class.
Studying at the same time every day is a great way to improve your score. Write down your study plan and sign it!
Divide study time appropriately
The TOEIC is divided into seven sections. Each section is worth a certain amount of points. Don't spend too much time studying one section. Many students make the mistake of studying the section that they enjoy the most. This is the section you should spend the least amount of time on.
You might want to divide your study week by focusing on a certain section each day. Remember, if Sunday is your day to practice Part VII (40 questions on the test), you might have to study twice as long as you would on Monday when you focus on Part I (20 questions on the test).
Build a strong vocabulary
Another reason students fail the TOEIC test is that they have a very limited vocabulary. The day you decide to take the TOEIC test you should make yourself a blank dictionary. Use a notebook (an address book works great because it is divided into letters) and keep track of all of the new words you learn along the way. It is not useful to study vocabulary lists. You will only remember words that you have seen in context. For each entry, write the word and use it in a sentence. At the end of each week you should write a short letter or composition using as many of the words as you can.