So far, I don't often
I pray with, or rather for, my son every night that I tuck him in. The Lord's prayer is way beyond his comprehension, let alone memorization, and the old "Now I lay me down to sleep" has always sounded morbid to me. Why would I die before I wake? Gives me the creeps. So I made up my own. It's simple and focuses on gratitude first.
Thank you Jesus for today
Thank you for my family
Protect me as I go tomorrow
In Jesus' name
Amen.
Some nights he repeats some of the words like "today" or "tomorrow." Sometimes he folds his hands along with me. He usually says Amen after me. Most of the time he's content to just listen and absorb it as another bedtime routine, which suits me fine. And some nights I actually forget. Fortunately, God's not checking an attendance sheet.
Another prayer we do together when we think of it is saying grace at the dinner table. I won't even tell you how rare this is, but we've nailed down a simple format that he'll memorize without too much trouble.
Bless the food
In Jesus' name
Amen.
Eventually I'll expand into other things like reading the Bible and praying with my son, and helping him express himself through prayer. But faith doesn't have to be complicated, because Jesus didn't come to start a religion. Simple is the way to go.