Start from the beginning. To become fluent in French, all students must start with the basics. Even if you already studied the language before, you must review all the knowledge you acquired until it becomes natural. This is the only way to increase your level, in order to finally reach fluency.
Stick with it. Make French language acquisition part of your routine. Devote a certain number of hours per week to studying its grammar, as well as to practicing listening, speaking, reading and writing in French. With the availability of free materials online there is no excuse: the free access to French language radios, newspapers and TV is now at the tip of our fingers. Be patient: no one can become fluent in another language quickly, so have realistic expectations regarding the time frame you set yourself to reach the desired fluency.
Practice the language. Take every opportunity you find to use it in your daily life. Some options include: placing flashcards with French vocabulary words throughout your house or workplace, changing your phone and social network settings to French, finding a French penpal to whom to write or a French-speaking foreign exchange student with whom to practice speaking, reading the daily news in this language or even listening to music in French. Involve the French language in your daily life, and you will notice the improvements that will lead you to fluency.
Evaluate yourself regularly. Perform self-assessments or have a teacher grade you, so that you will know when you are ready to access the next level of French, improving your way to fluency. Focus on acquiring the grammar, speaking, reading, oral and writing skills expected for each level of French, undergo an assessment, and if you are successful, you can access the next level of French with more challenging learning goals, until you reach fluency.