Introduce the creed, and explain the meaning behind the words. It will be much easier for children to memorize, and be more meaningful, once they understand what the creed is talking about. This introduction may need to take place over the course of several weeks.
Write the creed on a large piece of poster board and hang it in your home or classroom. Younger children may benefit from having pictures drawn to depict the words in each line. For instance, the first line, " I believe in God the Father, Almighty, Maker of heaven and earth" could be followed by a picture of the earth.
Help your child to write out the creed on a regular basis. This will reinforce memorization.
Include the recitation of the Apostles' Creed in any other prayer routines you already have. Recite it yourself at first, and then encourage your child to join in.
Put the creed to a tune and sing it. Song aids in memorization, and will make learning more fun, particularly for younger children.