Your students should use all the means!

All the means at hand! Studying, learning vocabulary and useful expressions, practicing them by using them in conversations and written sentences, talking with natives, losing fear to do so, trying over and over and making mistakes, reading readers or unabridged books, listening to a radio station on the Internet, watching movies... Let's tell them: You are so smart, you can't depend on me all your life, use the means, don't limit yourselves to what I teach you...