Graphic design contains underlying principles that govern the most important aspects of great design. These principles create the acronym C.R.A.P. which stands for contrast, repetition, alignment, and proximity. The well-balanced combination of these principles tends to create design which most people would consider visually pleasing.
To say a design is CRAP is quite the compliment (we suggest not trying this with your designer). The original term was coined by writer Robin Williams in his book “The Non-Designers Design Book” written in 1994. Here is an online pdf version of the book: https://diegopiovesan.files.wordpress.com/2010/07/livro_-_the_non-designers_desi.pdf
Creating a great design is more science that one might think. There are quite a few fundamental principles behind the scenes guiding and directing a designer to achieve great results. By simply following the four basic principles of CRAP (contrast, repetition, alignment, proximity) you’ll be well on your way to aesthetically pleasing design.