Leveling your turntable, your approach?

I would have to believe that the most important factor in "leveling" would be to make sure the platter was rotating around the axis perpendicular to the vertical axis of the bearing. Imagine extending the vertical axis of the bearing and proving perpendicularity with the horizontal plane of the platter.
This same logic would also apply to the pivot point of the tonearm.

I used to use a level and go side to side, front to back, and corner to corner. Now I use a circular bubble level. It is easier and I believe it has better accuracy because it shows 360 degrees.

If you want to spend a few bucks get a 12" digital level for very accurate readings. Available at your local hardware store. Start with platform, then turntable.
As we all know very important for the best tracking and playback.

Do your main bearing a favor in the long run and level the bare platter with an accurate level and/or levels.

I use selected bullseye levels that cost all of $2-$3 each.

The levels were hand picked by placing them on a sheet of plate glass which had been leveled with expensive/accurate carpenters levels.

Think I went through 50, or so, to find 3 that looked good.

The local Mom & Pop hardware store let me use their high end levels, plus a sheet of flat glass (been shopping there since the 70's).

I'd guess that measuring even keel with various LP's will give various results.

David, you are one dedicated tablesmith.

I don't like round levels; use one of those 4" line levels for framing. Place it along the path 'tween spindle and stylus. Level there is all that matters, I've seen too many platters that are level there but not here and everywhere. Makes you CRAZY!

Thank you all for your responses. I can tell that there are two "schools of thought" on this topic, one is 'Level the platter flat for the bearing', and other is 'Level across the stylus sweep' and that is where I have found differences in level readings. I do use an excellent 5" Empire spirit level as this provides the highest resolution of precision for what it is I am doing. I also appreciate advice on the digital level but I just don't trust these devices. I like the analog levels, no pun intended. I did find that on my Cardis Sweep/test LP that 'platter level' yielded supurb results, esp. no anti-skate issues. Thanks all. BR

I use a 'audiophile' bubble level which was precision machined for high accuracy, so I trust the readings.

However, I get different readings on the plinth vs the platter, and different readings at different spots on the platter. So, I decided it was where the stylus meets the record that mattered the most and I level it at the center of the stylus sweep.

Level the plinth and ensure the bearing is at a perfect 90 degree. Most platters are not flat but dished so unless you use a level from edge to edge you'll be defeating the purpose. I always ensure that whatever the platform the table sits on is dead level first so it resembles a series of parellel lines rather than angles to conteract and offset  each other. Critical IMO for suspended decks so springs are as equally tensioned as possible to support the weight as designed rather than an improperly used method of leveling.