Sometimes when working on a scene I'll make a playlist of music to serve as inspiration while I'm drawing. Occasionally, I'll find a piece of music that fits so well with the scene that I'll play it in the background while I pitch to the director. While working on an early version of the epilogue from The Croods I stumbled upon a track from Danny Elfman's score for Charlotte's Web. I listened to this track so many times that certain cues in the music inspired me to create new shots that I previously hadn't thought of.
A little background info. For a brief period the movie was bookended by scenes that took place in a modern day museum where a group of kids on a field trip learned about the 'Croodaceous Period.' Some of the things Grug is drawing on the rock reference ideas that were eventually abandoned. For instance, Eep spent the movie unsuccessfully trying to make fire and Thunk couldn't throw rocks well because, as it turned out, he was left-handed. Also, I put this together myself in iMovie so the cutting is not as great as it should be.