We just started having each of the kids have a quiet time before the Lord every morning. They can read the Bible, sing songs, pray or do all three.
Good habits are easier to form when you are young and I know for me making time consistently each day doesn't always happen. If I make it part of their routine in the morning I am more likely to get the time in myself. The girls had recently received Promise Calendars from their aunt with a verse in it to read for each day. They have loved doing that and both Steve and I wanted them to go deeper. We want them to have their own relationship with the Creator and not one that is based soley on mom's and dad's experiences.
So each morning I set the time for 15-20 minutes. The only rules about the time are that they are spending time with God and that if they would like to sing they find a spot away from everyone else so as not to be a distraction. Even our four year old did great. I had to re-direct him a couple of times but he did very well. It's a very serene and relaxing time.