When you are purchasing TOEFL lessons, you will want to make sure that the lessons are thorough and give you a chance to practice what you are learning. This is especially true with the TOEFL lessons for the speaking and the writing sections of the TOEFL iBT.
First of all, TOEFL lessons should be comprehensive in that they should prepare you for all sections of the TOEFL iBT. Second of all, after completing the lessons, you should be given a chance to complete speaking and writing practice tests so you can get feedback from a TOEFL iBT specialist who will evaluate your academic English proficiency and recommend specific lessons so that you can overcome your weaknesses and increase your TOEFL score.