i am sounddesigning for an animation film in which there are several scenes involving various interactions between two soft-looking balls. they collide, bounce, etc. i'm looking to achieve a stretchy, springy effect that will convey the ball's elasticity, mass and tension, before and during collision. as a starting point i've collected raw material such as plucked strings, rubber squeaks and duck-tape recordings. i've also experimented a bit with LFO modulation and recorded some nice-sounding bouncy effects. before i start processing the material, i wanted to ask for some advise or suggestions... how would you go about designing such effect? what type of processing would you employ?