Step #1: Sit down and take an entire TOEFL test.
(Note: You can get an entirely free TOEFL Practice Test by clicking my website)
Even if you have NEVER studied for the TOEFL before, I recommend taking the entire test.
Some people might not agree with Step #1.
Why?
Well, you might get overwhelmed and quit early.
You might get nervous and give an awful response on the speaking section.
You might start to write an essay response, only to realize you have NO IDEA what to write.
But take it anyway.
By taking the entire TOEFL test, you are being 100% honest with yourself. You get a real, clear look at exactly how much work you will need to do to reach your goal score.
After you have taken an entire TOEFL test, then move on to...
Step #2: Assess your TOEFL ability
What sections were difficult for you? What sections were easy?
What questions on the reading section did you get wrong? Which ones did you get correct?
What questions on the listening section did you get wrong? What was more difficult for you? The dialogue or the academic lectures?
Continue this process for each section of the TOEFL test - Reading, Listening, Speaking, and Writing.
Once you have finished your assessment, you know the aspects of the TOEFL test you must focus on when studying.
Create a list of these areas! Create a list of what was easy, what you struggled with, and what was impossible.
Step #3: Focus on improving one area at a time
Even if you struggled with all four areas, focus on one area at a time.
You could start with reading, then do listening, then writing, and finally speaking.
Or you could start with speaking (often the most difficult), then go on to reading, listening, and writing.
I recommend two things:
1. Focus on 1 area because it narrows your focus. When your focus is narrowed, you will see improvements at a much quicker pace.
2. Combine Reading/Writing and Speaking/Listening. So, if you start with reading, then study writing after. If you start with speaking, then study listening after.
Why?
Well, that's in Step #4:
Step #4: Completely immerse yourself in this aspect of English
If you've chose to focus on reading, then immerse yourself in as much written English as possible. Focus on reading for 20-30 minutes every day - and focus on reading material you ENJOY.
Combine this immersion with focused study on the technical aspects of answering TOEFL questions.
Bonus: When you work to improve your reading ability in English, your writing ability will also improve. This is why I recommend studying these two skills back to back.
Step #5: Once you've given yourself ample time to study (like, 1 month, for example), re-take the TOEFL test
This gives you a chance to see how far you've progressed in a relatively short period of time. Then, you can re-assess your ability and understand what skills you still need to focus on improving.
I hope this helps