Poor English is not a problem on this site, Eric!
I adjust the illumination to give the same exposure at all grades: My Opemus 6 colour head has four filters: C, M, Y, and N. The N is a neutral filter giving two stops fine-tunability.
It just so happens (intentionally?) that my EM10 exposure meter will give the lightest near-white a reading of 85 on all grades of Ilford MG IV RC at 10 seconds exposure. So I twiddle the "N" until the EM-10 shows 85 for the densest part of the negative that I want almost, but not quite, white.'
The meter setting at the thinnest part of the negative (my shadows) determines the grade needed to fit everything onto the paper without burning/dodging. I have a diagram made up that I consult.
So I start without filter, adjust "N" and aperture to give 85 in highlights. Then I measure shadow, determine wanted grade, set "Y" or "M", then change aperture and "N" until highlights are 85 again. Expose 10 seconds, develop and fix.
Then I'll probably decide that the contrast is too flat, change the settings again, and start burnig and dodging. But I stick to that 10 seconds base exposure.