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Forget the compass. Your mount probably has a better solution built-in - the declination setting circle, plus the a=stars above you - and this beats drift aligning too.
My sequence:
1. Level the mount using a bubble level.
2. Choose a bright star on the meridian, near the zenith. Set the dec circle to read the dec of this star, clamp the dec axis and adjust the mount altitude to get the star centred in the scope (at low power).
3. Choose a bright star near the east/west horizon, the lower the better. Set the dec circle to read the dec of this star, clamp the dec axis and adjust the mount azimuth to get the star centred in the scope (at low power).
Check a few stars around the sky to confirm that their decs read correctly from the circle - if not repeat steps 2-3.
Doing this should align the mount on the south celestial pole within the resolution of your dec circle or better, and its a lot quicker than drift aligning. If you have encoders ... nirvana.
There is one issue to be aware of - whether your dec circle and scope are aligned - they may not be. To test this, you set up the scope and do the following in daylight:
a. Choose a target on the horizon and point the scope to this and centre in the FoV. Record the dec circle reading as A.
b. Flip the scope over the mount so its on the other side of the polar axis, and align on the same target. Record the dec circle reading as B. Lock the axis and do not move the scope.
The correct reading is the average i.e. (A+B)/2.
Adjust the dec circle or the scope cradle so that when the scope is on the target, the dec axis reads this value.
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