The Wake Up Later blog features a list of 8 mistakes that web developers make. These are not the glaring mistakes that are plain to see, like covering a page with animated GIF graphics or writing the site’s HTML in some awful WYSIWYG program.
The mistakes show a lack of polish and design savvy. There is a difference between Arial and Helvetica. Using cruddy stock photos can ruin a good design. Have you thought about the color scheme…or are you going to use the same blue and white pallete again?
Even if you are a rockstar-level web designer, this list is worth a look.