It is difficult to advise on settings or filters because it will depend on the light and dynamic range at the time.
As you are after mist I assume this will be a dawn shot, therefore if you are not shooting into the sun, the dynamic range will probably not require a grad filter. Just take a test shot and check the histogram, if you can get the full range without clipping then you are fine.
If you are shooting into the sun or the dynamic range is too great than you can use a nd grad, check how many stops the sky is (not the sun) brighter and use an appropriate filter.
Likewise polariser depends on the angle of the sun from your lens, so you will need to experiment with this.
Settings wise, use your base ISO (100 or 200) for best quality, use a tripod because it will be a long exposure, aperture will depend on how much dof you require, so if you have something close as foreground then you will need a smaller aperture such as f 14 maybe or f 16, if you are shooting a vista with no near foreground then you can try f11.
Shoot on manual and set the shutter speed to give the correct exposure and do a test shot, check the histogram, if there is clipping use a grad filter or take a second shot for the highlights and manually blend if you prefer.
I can recommend reading 'Understanding exposure' by Brian Peterson for a fgood understanding of the exposure triangle.
Good luck
