CERTAIN celebs always give good cleavage.

Jessica Simpson, for instance, consistently nails the art of chest-dressing.

Her artfully enhanced breasts rest comfortably within whatever top she wears, and they are always well-supported from underneath, creating a side-and-front view that’s attractive without creating the tacky “Water Balloon Effect.”

Other high-wattage women aren’t as skilled. From pushed to smushed to formed and fabulous, here’s the best and worst of celebrity cleavage: look and learn

DO: Jessica Simpson

There’s plenty to display in this pretty dress – but Jess doesn’t O.D. on the push-up factor.

DO: Jennifer Love Hewitt

Miss Love Hewitt’s large chest is well-supported by the structure of the dress; everything is kept perfectly in place.

DO: Cameron Diaz

She’s no D-cup gal, but Cameron’s cleavage is always cute. Deep V-necks can create the illusion of larger breasts.

DON’T: Paris Hilton

Never wedge an object in your cleavage, no matter what your size.

DON’T: J.Lo

Ouch! J.Lo’s cups runneth over – a little too over.