1. Do not be overly concerned about grammar.
Think about kids for a minute. Who learns language faster than children? Children do not start with grammar, they start with words and phrases and learn to talk. Then they learn to read and write. Grammar comes naturally as one gains proficiency in the target language. Perfect grammar is almost never used in everyday life. The average American has very little scholastic knowledge of grammar yet they usually recognize poor grammar when reading or listening to English.
2. Keep inputing the target language into your mind, even when you don't understand it. Take a class. What you hear and read will return to the surface of your mind with repetition. Children do not understand all that they hear but they receive the input and later are able to use what they have heard. Movies, drama, television, and music are also good sources of input. Be sure to also watch them without subtitles. Remember, there are no subtitles in real life. Textbooks are also good input, but we tend to ignore our own voice (I think this forgetting mechanism keeps us from going crazy with our own thoughts). Anyway, we tend to remember another's voice better than our own so if at all possible get a native speaker to help with the textbooks or record them for you.
3. Keep a list of words and phrases in your pocket. Review it frequently during the day.
4. Label the things around you, in your house, your car, at work. Yellow post-its work great for this.
5. Last but not least, spend as much time with native speakers as possible, and that in varied situations.
Learning language is a lot like a snowball rolling down a hill that keeps getting bigger as it rolls. We must first put together a snowball of sufficient size and then start it rolling, after that it will grow on its own so long as there is enough momentum and plenty of snow around.
good luck!