Irregular Semi-Perfect Collision

I have a bunch of different Movieclips from about 10 different classes moving about the stage. What would be the fastest/most efficient way to detect collisions between two of them? They can overlap each other a bit before the collision is detected, so I thought the easiest way would be to draw a couple rectangles that take up a majority of the object for each class and use hitTestObject to see if any of the invisible rectangles of one instance are colliding with the invisible rectangles of another. Is this a good method? I figured that since a bit of overlapping is okay and actually preferred, that two or three rectangles can easily take up all the room I need for each object.