Create songs with your child containing multiplication tables. The repetition of the songs is what they will remember, likely even as teenagers. If your child is struggling with the song, put on some instrumental music and let them sing.
Go online and access special creative games and programs to assist with memorization of the multiplication tables. Among the possibilities are "Rap and Learn Your Times Tables" with MC Ant Tanna, which is $19.99 as of Jan 2011, or visit Multiplication.com, a free website to build math skills. Games help children learn and keep them engaged while learning.
Repeat the methods with your child. Repetition is the key to learning the multiplication tables. Add new games or activities for children to keep them interested in learning.
Test your child frequently to ensure he or she is retaining the information properly. Make adjustments to your learning schedule based on the method that is working best.