Start with greetings and common phrases (hello, how are you, etc.) and the most common words (ball, milk, cat, dog, daddy, mommy)
Increase their motivation by rewarding them for learning extra words or phrases (e.g. , icecream, a chocolate bar, a trip to his/her favorite place, such as an amusement park).
Surprises are proven to increase motivation. Play games like hide and seek (count in the 2nd language) or peekaboo (for babies).
Make the activities fun by playing language games or going on to field trips. You can go to the zoo and name the animals in the 2nd language or play snakes and ladders.
Children will lose interest if the task their given is difficult.Ask them to learn only a few words at a time, they will find the task more enjoyable and increase their confidence.
Continuously test your child’s knowledge. Instead of a written test you can use worksheets or just ask simple questions like show me your “はな”(nose) or give me the ”ボール。”
Have a clear goals about your target for the end of the year. Do you want to teach a) greetings and basics b) conversational competence, c) reading and writing skill, d) native level competence, e) etc..
Applications and language DVDs are good but also use traditional hands on materials such as flashcards and picture dictionaries.
Ask grandparents, neighbors and relatives if its OK to have a skype chat with them. Also you can join facebook groups, online forums etc. to connect with likeminded people.
Let your child’s kindergarten teacher or caregiver know about your aim of raising a bilingual child. They will make sure your child does not experience any problems among his/her peers.