*In general, more expensive one. If I pay more, I want a better product.
*Mascaras and liquid eyeliners. I have sensitive eyes. I have to be wary about fragrances, colorants (especially black — often minute trace of nickel in the oxides is to blame there), and acrylates (especially in waterproof formulas). I can only wear a handful of brands.
*Eyeshadows and eyeliners. I want pigmented colors that will work with my oily, somewhat hooded lids. I don’t want anything too stiff, too chalky, or too powdery. I can’t wear most cream eyeshadows.
*Foundations. I’m hard to shade match. My body chemistry and face oils like to oxidize and discolor things. I have sensitive skin. I’m picky about fragrance, coverage, finish, weight, etc. due aesthetics and sensory issues.