If you already know basic French, the best thing you can do is to find somebody to speak French with, read French books, watch French films etc. The best thing for acquiring a language is real life practice.
Also, some people are embarrassed to speak a language when they still make a lot of mistakes in pronunciation and grammar. This is a disastrous attitude for acquiring conversational skills in a language in my opinion. You need to have the courage to try to speak French and not be too embarrassed about the mistakes you will make. Hours of studying with grammar's and vocabulary lists and whatever, the school method, is really inefficient. If I look in my own country, almost everybody except older people know English as a second language. This isn't due to school, but due to internet, media, movies et cetera being in English. Most children nowadays learn English before learning it in school or doing any study, because they are exposed to it. The school just refines their grammar a bit.
Duolingo or Rosetta Stone can help you get started or help you to be exposed to French a bit every day. I don't have any experience with Rosetta Stone, but I've personally found Duolingo to be somewhat helpful for acquiring basic skills and vocabulary in Spanish and French, but for any more than that in my opinion what you really need is real life practice.