If you are already well read in Russian, but I can't master speaking, the easiest thing to do, of course, will move to Russia for permanent residence and to learn to talk in direct constant communication with native speakers of the language. However, if you have not as far-reaching plans, attend only with the teacher for whom Russian language is native.
Practicing with a teacher, try to be active. Don't wait until the teacher himself will offer you a possible job. Make up interesting questions to study the subject, remember some interesting history (or anecdote) and offer to tell her in Russian. The teacher will appreciate the student initiative, and it will give you and additional material on topics outside of them that you can and to master the language.
Determine what related to the development of conversational Russian speech, you prefer to do: to teach short informal expressions, memorize dialogues or texts, to write and to memorize aphorisms and Proverbs, to retell or spontaneously try to talk on the subject. You can only do what you like, and you can alternate the various methods of teaching Russian language.
Concentrate on what you are going to say that it will be interesting to both you and your companion, not on how you say it. Consider which topics you are really interested in what topics you like to discuss in their native language. Imagine where and when you can begin to speak on this subject, and who will be with you to talk about.
Take a piece of paper and write about what's bothering you in your speaking as much detail as possible: what topics cause the most difficulty, what exactly would you like to learn in the first place. Learn all this will be faster and lighter than any material in the textbook of the Russian language. Of course, this tutorial is also not canceled, just this motivating material will be your point of reference for understanding the intricacies of the Russian language.