Excuse my grammer, it is poor. I design for a living, and write last 🙂
Principles of Design is pretty much all about proximity, alignment, repetition and contrast. With these elements in hand, you should be able to make something at least pretty decent. Pretty much it all boils down to how you want someone to look at your design. If you just have a ton of different fonts, and different sizes, no one will know to begin. I supplied an example of what I think is a good example, and a bad example.
What I think is a good example is a back of a DVD cover, now here I have the credits up top and the same size font in each line. I feel with all the credits and legal stuff, the credits should always be first. Below the credits I have two websites, These websites are the next bit of info I want people to know, also the DC logo, so they know it’s a DC movie. After the Links, and the soundtrack available, we get to the legal information, now this is important, but a small font is the way to go on a DVD design, as consumers don’t buy a DVD so see oversized Legal info. Below all that I have my logos, I have them spaced equally apart, and the rating the biggest, as I feel it is important for consumers to know.
This is a bad design, the reason being, well it’s so confusing. I a big website url up top, and a smaller one in the middle, so to me, this larger font website must be more important. In the credits I have a few names a larger font, so they must be more important. The alignment of the credits and legal info is all mumbo jumbo, to confusing to look at. Last, the bottom where the logo’s are, well very confusing, the alignment is awful. So to me the principles of design are very important, and have a great impact on everything you design.