I cringe every time I se the suggestion to donate a botch to charrity. I think most people can tell if something is decent - or not.
As to improving the overall quality - perhaps assume that no one knows anything and start with " classes" as to what is acceptable.
Maybe start with what fabrics are suitable and which are not
How to cut accurately - and perhaps how to choose a forgiving pattern
Stress the importznce of an adequate and consistent seam
How to press " for quilting"
Perhaps show examples of what you are looking for - and if you can find bad examples not made by amember of your group, show that and explain the problems with it