Well, honestly, I avoid Guess. That is because of a profound antipathy for a former (perhaps present? I don't know) celebrity spokeswoman who almost perfectly represents everything I don't want to be. (Funny story there. My son was once trapped in their outlet on Rodeo Drive, accompanying some friends who were shopping. Pictures of the afore-mentioned celebrity were plastered all over the walls. He made some comment and the SA gushed, "Oh no, no, she is wonderful! So nice! After he left the store, she came running out and told him that she had just said that because she had to on the job, that the woman was actually really awful.)
I am seriously considering getting informed about labour practices too, and avoiding stores or brands that are guilty of flagrant exploitation.
Other than that, I prefer to be loyal to stores that consistently come through for me, so they are my go-tos. Not that I refuse to go elsewhere, but my primary constraint is limited energy, so it makes a lot of sense for me to start with stores where I am more likely to find things. I am certainly open to discovering new ones though, which is why I like listening to you guys.