I'm in the same boat. The only signal that I still trust is (for want of a better term) governance longevity, i.e. how long has the company/brand been under its current management structure. This requires some digging, but good salesmen are usually well aware of management changes at their brands. That may not apply to generic clothes shops, but in my experience this still works for tool shops and appliance stores. You'll want to talk to tradespeople though, not sales drones.

Then there's two signals that negatively inform my trust of a brand:

- company size: the larger the company, the lower they start on my trust ladder;

- advertising: when a brand is overly present in the public sphere, that to me signals that they're overcharging for their product.