I throw the camera at the brightest section of the pano, meter off the foreground then drop on the right GND to bring the sky back into check. I either set the AE-L in aperture priority (I have my camera set to lock until I press the lock button again or until the meters turn off) or drop it onto manual mode. My rule of thumb is expose for the highlights, and in a pano that is wherever the brightest frame will be. Seems to work ok in my case...