From my experience. I do it in this way. First Find a tutor on Italki, a real professional teacher but not a conversation tutor. Causual talks do not help me much. They can offer you some structure courses. The structured course might not be fun, but it is very useful and efficient. Second Find a topic with you want to talk about. You need to explain all your opinions in English, then you will be pushed to learn some new words and sentence structures to build your sentence. Third First write a essay about the topic, we are not native speaker. When we are writing, we are not in a hurry .we have time to refine our essays and look up some new works on tje dictionary. This is a process of learning. You can definitely post your essay here for others correction. Fourth Make the essay a presentation, This requires you to get familiar with the language knowledge because you will give a presentation with as less hesitation as possible. Fifth Make the presentation to your teacher, and while you are giving a presentation, let your tutor wtite and your mistakes. After the presentation , Let your tutor correct your mistake. And before they correcting your mistake, just let him point out the mistake and try to do a self correction first. Sixth You have already made a presentation, but it is prepared. There should be some surprise. So just let your teacher ask you aome random question according to your presentation. The you have to answer this questions immediately, that will be a challenge. Seventh Review. And for me, I don't change the topic often. I am Recently learning English with a physics textbook, and I am always talking about physics, after I can totally handle it, I will change the topic or subject