Although learning a language is harder as an adult than as a child, here are a few strategies that can help pave the way:
Watch social cues: Pay attention to nonverbal cues, such as eye gaze, gestures or pointing. They can enhance your understanding of sounds, words, phrases and even grammar.
Sleep on it: Going to bed soon after drilling vocabulary or other practice can help consolidate what you have learned.
Listen to your own accent: You can improve your pronunciation by recording yourself in conversation (as opposed to reading from a script) and practicing with a native speaker.
Tune out to tune in: Listening to language spoken in the background while doing another task can help you learn to distinguish among similar sounds.
Say it again: Hearing and repeating words and phrases can help you learn them faster and recall them better.
Immerse yourself: Of course, nothing is more effective for learning than complete immersion in the culture. Living and working with native speakers can round out this experience.