a lot of it is personal choice based on what the quilt will be used for. Feel of the fabric is one of my first qualifications - and you've probably already notices that there is a difference in quality in this area. Another is thread count..without knowing the thread count like we do in sheets, you can guess the lower thread count fabrics by trying to see thru them...if you can see shadows or identify specific things thru the material then it's too thin for me. Another is the print/colors - in cheaper fabrics the printing can be off=register, meaning that second printing of color can be not correctly positions so that colors don't line up with the basic print of the fabric - these are no-no's for me. Almost every store has various qualities so I just need to look to find what I want.