Begin with information that establishes the "who, what, why, where and when" of the event.
Lets stay with the example of a child's birthday. Did you send invitations to her friends? Use a shot of the invitation to begin our tape. For visual interest, maybe prop the invitation in front of the birthday cake, or in front of some balloons and party hats.
How about putting colored alphabet blocks that spell out the invitation information on top of a brightly colored birthday table cloth? Or shoot a short sequence of Tommy pasting lines of the invitation onto colored paper? Or show the invitation hand-lettered onto a blown-up balloon? Let your imagination be your guide, but do something that signals the start of this event.
Show the story of Tommy's birthday with your camera. If your friend called you on the phone and said "I'm so sorry Bobby and I missed Tommy's birthday party. How did it go?" you would launch into a verbal description of the various events that made up the occasion.
Do the same thing with your video. Capture the sequence of events that shows (tells) the story of Tommy's birthday party. How about:
There's nothing fancy here. All you've done is follow the events of the party as they unfold. The point, though, is that you had a plan, and tried to follow it.
Going home -- A shot from the street, as Tommy's friends come out the front door of your home. A final shot from inside the front door, showing Tommy waving from the door as Mary Lou gets into her dad's pickup. Follow the truck for a few seconds, then let it disappear out of the frame.
To see how effective this kind of planning can be, look at our short video of a bateaux mouche excursion on the Seine River in Paris, the result of planning but with vey little editing involved.