The SM for particle physics is surprisingly successful.
It is based on symmetry principles of various types.
I will first recapitulate basic assumptions and key aspects of the SM,
emphasizing differences between global vs. local gauge symmetries.
Then I will apply similar assumptions and aspects to the DM model buildings.
I will discuss a few exemplary DM models and demonstrate theoretical/phenomenological
importances of my approach, in particular unitarity and theoretical consistency.