One way is to focus on the family values that are presented in Modern Family. For example, you could write about how the adults in the family pass on these values to the younger generation. You can also create storylines that involve the adults learning from each other. Let's say Jay teaches Phil some life lessons about being a man, and in return, Phil teaches Jay about modern technology. Keep the story PG - rated by avoiding any explicit content. Also, make sure the plot is engaging and not just a rehash of what's already been shown in the show. Try to introduce new elements like a new character who is a friend of the family and how the adults interact with this new person in a positive and appropriate way.
First, focus on the positive relationships. For example, write about the love and support between the married couples in the show, like Cam and Mitchell. Second, use humor in a clean way. You can write about the funny misunderstandings that happen between the adult characters. Third, avoid any sexual or overly suggestive content. Instead, concentrate on their emotional and mental growth. For instance, how Claire learns to be more assertive in her career.