Nothing beats actually talking to people. Preferably natives. There are plenty of ways to find Japanese people to talk to, as long as you're comfortable with the idea and outgoing enough to actually do it.
There's also "shadowing", which is where you listen to a native speaker and repeat what they say out loud. You can do this on renshuu. Play the audio for words/sentences and try to repeat what you hear.
I'd also recommend narrating your life, which just means you talk to yourself :D Try to explain what you're doing right now, for example.
You also need to listen to lots of native Japanese. Just keep in mind listening alone does very little for your actual conversational skills.
