Some theorems of design

Banana split: sensory bombardment
We humanoid life forms love to bombard our senses. The more the better - the experience seems heightened the moire sensory receptors we can excite. Examples: An ice cream sundae with vanilla ice cream, hot fudge, salted pecans, whipped cream, and a cherry has sweet and salty, hot and cold, creamy and crunchy, and light and dark. Um, we love it. A hamburger with 'the works' has hot and cold, crunchy and soft, sweet and salty, tart and smooth, and more. And we like it when it has the variety to excite more of our senses.
However, all the ingredients need to be in balance, if there is too much mustard, it throws off the balance of the burger and we are not so enthralled. In design, keep in mind that the reader/viewer may like a more sensory experience, but elements need to be in balance.

Artificial authenticity

You know in the movies when they show someone looking through a pair of binoculars? On screen they show us 2 overlapping discs representing the 2 barrels of the binoculars. That is what we expect to see and it is what we have seen in almost every film that shows a binocular view. But, the reality is that when one looks through binoculars, the 2 images merge into a single circle of the view. But the truth would not communicate as clearly to the audience. They stretch (or lie) to the authentic to become artificial. And, for them, it works.

Too close for comfort

I suspect that you have been in a friend's house and noticed that a picture on the wall was a bit crooked. (above right). It probly annoyed your sense of order. If an object is alifgned with other elements (left above) or at an angle that is clearly intentional (middle), we are more comfortable with it. But when it is off just a bit, well, that is too close for comfort. Many of us cause a diversion and go straighten the offending object.

Blinking stoplight: user education
Figure out

Freeway passing: personal pace
Not to get there first, we just prefer to drive, or walk, at our own personal pace. all different for each person

Target spill
An ad or piece of graphic design is aimed at a specific group of people. But sometimes, people on the fringe edges are also paying attention and

Ease on down: smooth transition
FLW, take by hand, not yell from across the room.

Familiar innovation
All design decision are compromises - actually, all decisions are compromises. To gain something, you have to give up something. Sometimes, its an easy choice, because its 90 versus 10, other times its tough: 50 versus 50.

Grand foyer: building confidence
1st impression, grab audience, user.

Order in the court: comfort of order
Not much we can agree on as carbon life forms. But the vast majority of us do prefer a sense of order.

Figure out what's working; exploit that and minimize the rest. Conveys grabbing and wrestling and pushing to the limits.

Seduction of technology: theory
We become enamored by the coolness and push the function and benefit to the back.

Clarity, not simplicity
GD is hardly ever about making something simple. GD is about making things clearer. One way to achieve clarity is often to make it simpler. But simplicity is not the the objective, clarity is. Clarity can be achieved by improving many elements: contrast, color, placement, size, etc.