I usually run two HQ units, a daemon prince and a Bolt Of Change sorcerer, maybe with Wind of Chaos also, if I feel like it. I stick him in a unit with some Chaos Space Marines and have him throw lightning bolts out the top of a rhino.
The Demon Prince comes behind the rhino line, ready to fly out and open up a dreadnought or monstrous creature when it appears.
After that, It's down to regular old Chaos Space Marines (in rhinos) and the heavy support choices. A havoc squad with four missile launchers (in a rhino), maybe a suicide squad of Chosen (in a rhino!)
Basically, I put a million bolters and meltas in metal boxes and make 'brrrrrm' noises as I push them up the field, firing the can openers out of the top hatch.
I would run bikes in full squads of ten, if they didn't utterly suck. I'm a hardcore fast attack fan, but I picked the wrong codex for that! Here's hoping for a release this year, with cheaper fucking bikes!
I also model my chosen to be doing the 'standard, slow badass' walk, guns slung over shoulders and grenades hefted in hands.