The middle finger thing is very selective to me, I very rarely use it. When I do use it though, it means someone has seriously offended me, and might have even threatened me, for no good reason. And yes, words come with that finger, but again, I rarely do anything like that, unless I've encountered an asshole.

Now, what I personally define as 'trashy' is people that leave literal trash around their homes or vehicles. People that can't be bothered to properly throw their stale food away, throw their paper plates under their bed, and then fucking wonder why they have rats and flies around..