Introduce the French culture to sixth-graders before you begin language learning. Sixth-graders have been immersed in their own culture, and are also learning about cultures around the world. Teaching them about the French culture as you start to teach the language allows the students to make a personal connection with the language's speakers.
Introduce the French words for basic greetings, such as "Salut" and "Bonjour." At the same time, introduce the French phrase for introducing yourself; "Je m'appelle" followed by your name. This will encourage students to have conversations with each other and begin their instruction in French.
Move through French units, starting with words and phrases familiar to students already, such as vocabulary for items at school and home. Then move onto vocabulary lessons about people, colors, days and months, and standard phrases. As you move into more advanced vocabulary, teach verbs and conjunctions along the way.