[Arkady]

Being blessed with cameras that are issued, I can get quite brutal with my sensor cleaning, safe in the knowledge that if it all goes horribly wrong, I get a new camera.
While this is out of the question for most users, it does mean that I can try out techniques that others would balk at with thier own personal kit.
Using sensor swabs and cleaneing fluid on the sensor, then a dry swab to get the smears off (is that screaming I hear?) works a treat, even if the cameras have been in the deep desert for a while.

The best method is of course prevention. Only change lenses with the camera switched off to minimise electrostatic 'suck' and even then, only in as dust-free environment as you can manage. I use two bodies and never change lenses outdoors. Ever.