I suppose when I look at other people's quilts it is colour, followed by design...complexity can be great, but there have been some very simple patterns that have outshone some of the more "detailed" designs. Intricacy of the quilting can be fantastic, but there have been some simple big stitch examples that have been outstanding.
As for squaring up and lump free....well I am critical of my own if they are not "up to scratch", but I don't look for that in the work of others.
Don't think I really have a "method" for deciding what's gorgeous....just what appeals at the time.