The best way to pass the IELTS is to understand what the exam will ask you to do. There are four parts; reading, writing, speaking, and listening. 

On the Internet you can find a lot of free tests, and all of the resources you need to practice. However, to be successful you need to be able to speak to a teacher who knows the exam and can advise you on how well you are doing for the level you want to achieve. 

Hi Ghuffran. I have taken ielts this year. I'd like to say you need to buy some real-exam materials to practice and you'll have a rough idea about how much score you may get. You may be disappointed to see your real level at the very beginning. The exam has its own question types which you can find them hard. But it's a matter of time and attitute. If you can't figure out what to do with your weakness in some types of article or listening or something else, you can surf the internet and see how others achieve their success and how they did it. I also purchased The Road to Ielts--online preparation. It cost RMB 400. It's helpful. You can practice a lot. My Ielts overall score is 7.5, listening, reading, writing, speaking respectively 8.0,9.0,6.0,6.0. Writing and speaking are my weakness. And for me, they are the most difficult parts. You can pay attention to them. Best of luck! 

The best way is to study a lot. There is no secrets, but you should get a good grade on the oral and written test in order to do well on the exam.

@Adel, the IELTS certificate is an international exam that means students everywhere in the world can compare their results and know they have the same level of English. 

As well, the IELTS is used by universities for new students, and used by governments around the world for immigration visas. 

Excuse me, I'd like to ask a question: Except knowing their level, why do people take ILETS ? How can its certificat help you ? What is good for ?