The best example I can think of is a wheel with spokes.
1) Create one line and then convert it into a symbol.
2) Now create multiple copies of the line symbol and rotate them to create the spokes.
3) Now create a circle and turn it into a symbol.
4) Now make another copy of the circle symbol but make it a little larger then the first circle.
5) Now place these circles around the spokes.
6) Turn the the circles and spoke lines into a symbol (your wheel).
7) Create a motion tween of the wheel rotating clockwise once.
8) Create a copy of the wheel symbol so you have 2 spinning wheels
9) Make some more copies of your line symbol and start to create your van and street and houses
10) Combine some circle symbols into cloud shapes and have them continually float across the sky
11) You go from there...
The point of all of this is the whole scenario I created was built off of 2 symbols, the line and the circle. Don't keep creating objects over and over again if you can reuse an object. If your going to use flash, especially for an intro, keep it small