This list has probably been touted more than enough on the Internet and Design circles. I recite Deiter Rams 10 Principles of Good Design on the small, off chance that you haven't already come across them before. Even if you are familiar, it is always necessary to refamiliarise yourself from time to time.
These are basic, and all encompassing, and can be applied to practically anything that requires meaningful thought and planning. Here we go:
01 GOOD DESIGN IS INNOVATIVE
The possibilities for innovation are not, by any means, exhausted. Technological development is always offering new opportunities for innovative design. But innovative design always develops in tandem with innovative technology, and can never be an end in itself.
02 GOOD DESIGN MAKES A PRODUCT USEFUL
A product is bought to be used. It has to satisfy certain criteria, not only functional but also psychological and aesthetic. Good design emphasises the usefulness of a product while disregarding anything that could possibly detract from it.
03 GOOD DESIGN IS AESTHETIC
The aesthetic quality of a product is integral to its usefulness because products are used every day and have an effect on people and their well-being. Pnlu well-executed objects can be beautiful.
Find the other 7 principles and a bonus image after the jump: