I think we're expecting something complicated, when in reality, we just need to simplify. Here are my simple observations for this awkward stage:
Make it a habit of praying Scripture for you children. This insures that you are praying within God's will for their lives. For instance, pray that your children will "walk in truth" (III John 1:4). Do they struggle with making wise decisions? Pray for the Lord to "cause them to know the way wherein they should walk" (Psa. 143:8). Are they facing multiple temptations? Pray that the Lord would "deliver them from evil" (Matt. 6:13). As I study God's Word daily, prayer requests flash from the pages and I boldly ask the Lord to work in the hearts and lives of our children. Every day that we're on this side of heaven, we should be praying for our loved ones. While we're praying for them, it helps to pray that we will have the wisdom needed to be the right kind of parents. Contrary to popular opinion, we don't always know what we're doing!
When young adults graduate, if they don't immediately take a job elsewhere or marry and move into their own homes, there may be an awkward phase of "Where do I fit in?" to go through together. Pray for direction, but don't try to be a traffic cop at this point. You figured things out, didn't you?