I also mostly buy dresses, since I find they are easier to wear.
You only need a matching cardigan and tights and I find them more comfortable than thick jeans fabric.
For a layered look you can wear leggins under many dresses or even skinny jeans.
Mango: is like my special occasion kind of shop. I tend to get something there maybe once a year after getting some extra money for x-mas. Their dresses are lovely, very good quality.
Goodwill/ thrift stores:
Unwanted pieces are not always bad ^^, I have found many stylish pieces at these type of stores.
Once in a while they have nice pieces that don't fall apart right away ;)
A little plain sometimes but I have found a few nice items here as well.
American Eagle: rare
No name stores and brands....there is usually about 10 good basics or cute items within 300 tacky pieces.
I am talking about the stores that sell these thin fabric pieces ;)
All in all I wear 80% H&M and the rest I just find here and there...
I think it is less the brands that make the outfit, it is about buying and combining the right pieces mostly :)