One other element of family worship to keep in mind is the importance of joy. Is Bible reading drudgery? Is catechism and Scripture memory no more encouraging than making out a grocery list?
Surprisingly, some parents have the capacity to keep doing family worship for years without the least bit of joy. They're usually doing it to impress others in the church. I'm know because I think I'm one of them. I remember the sudden and painful realization that my leading of family worship was absent of joy when I visited another family whose father radiated joy when he spoke to his children about Jesus and the gospel. He made grace sound amazing, Christ sound great, and the Bible a dear gift. I found out later the verse he has in mind as he leads his family in worship is "Serve the Lord with gladness", from Psalm 100 I believe.
Not only will children detect a parent's hypocrisy in leading family worship without sincerity, but it is also dangerous to their salvation. They are likely to dismiss the faith as something that doesn't satisfy, as just one more thing their parents are doing to get them to behave. So, as we lead our families, let us remember to serve the Lord with gladness!