Measure stellar parallax angles Use Earth as the baseline. Relate spectral type to luminosity in calibrated H-R Diagrams. Works OK for individual stars. Distances to nearby galaxies. Other Techniques Tully-Fisher Relation for Spirals.
Distant galaxies are smoother than close ones.
All rely on previous steps, especially Step 4. Argue endlessly about the details. Less precision than Cepheid distances. Gives measurement of the Hubble constant. Redshift Distances Calibrated by all previous steps.