General Rules of Good Design and Layout:
When typing, use one space after punctuation.
Use fewer fonts - just because you have 500 fonts, doesn't mean you have to use them all on one page.
Limit use of centered text - large text areas should be aligned left for readability.
Balance line length - get rid of widows, those lone words hanging out on a line all by themselves.
Don't type in all caps - Caps are GREAT for calling out singular items. Overuse is overload, making it look like you are screaming at me.
Typographical punctuation - curly quotes are pretty.
Use frames and borders wisely - not everything needs a box around it.
Less clip art - photos are more inviting.
More white space - gives the eye and mind a place to rest.
Think elegant and sophisticated. Remember, less is more.