Contrast
Avoid using default gray backgrounds. Be sure graphics and fonts clearly contrast background color or image.  (Don't leave background set to default; if you want to be certain it is viewed as white, select a white background.  Avoid colors or backgrounds that make your text difficult to read.)

Alignment
Textual and graphical elements should be aligned along one or more straight edges.  (Don't center everything by default.)

Repetition
Repetition of font size, design, color, etc., can help unify sections of a page, or pages within a site.

Proximity
Group similar elements in close proxmity.   (Advanced users may prefer to use tables for more refined control.)

Some examples:

               Elizabeth Cooper's Projects Page
               English 652:  Professional Writing
               English 651: Writing Hypertext
               Michael Keller's Homepage

Compare several generations of site design:

     creative writing, professional writing, teaching writing
     lit-web-erature
     Elizabeth Cooper's 1996 web presentation on research