Adjusting type size is not a matter of taste, but a matter of reading distance.Oliver Reichenstein
It is the typographer’s task to divide up and organize and interpret this mass of printed matter in such a way that the reader will have a good chance of finding what is of interest to him.Emil Ruder
If an element is purely decorative and serves no purpose, then it serves no purpose. It’s a distraction. Good design is purposeful. Every typeface, image, ornament, shape and colour must have a reason to be.Sean Adams
Might not be the prettiest, but nevertheless one of the best collections of graphic design rules I’ve read to date. Recommended.