Let's discuss purely technical aspects of icon creation
1. Lines, slopes
One of the vital parts of the composition is the outline of the object, i.e. solid line, which limits the object from the rest of the image. When creating large-scale graphics, the designer rarely cares about highlighting of objects with complementary outlines. This is not needed because of the scale: even non-contrasted objects do not blend into a single whole. Pixel graphics is different. Two variants are available: either object and background colors have to be from different sides of the color wheel, or the foreground should be separated from the background by visible lines and shadows. I would like to discuss lines in more detail.
If we think again to the big-size images, we can note that in order to highlight edges, we can use all (including the most complicated) angles, Bezier curves and borders. Anyway, the line will appear perfect thanks to anti-aliasing. When shrinking the image scale to the small icon size, situation changes greatly. When each single pixel is equally valuable and can ruin the overall appearance of the icon, anti-aliasing is just unreasonable. It comes that you have to think about the possible line angles.
The angle you select for the line, determines the step of this line. This means that each line consists of basic elements, the union of which determines its neatness and visual appeal.
For instance, a 18-degree angle contains many small 3-pixel lines connected using a 1-pixel downshift:
This is how almost every line looks like. Basic element followed by joining followed by second primary element. However, not every slope creates lines that look look neet and not messy.
For example, here are 25 and 20-degree angles:
It can be easily known which line is more appealing. The 25-degree slope makes a line consisting of equal 2-pixel primary elements. The 20-degree angle has a basic element consisting of three parts: 3-pixel, 3-pixel and 2-pixel. The slope is more complicated, therefore, when not supported by other visual effects, it brings a feeling of messiness: the primary elements have contrast which is too obvious to hide from the human eye.
Now we can see the first conclusion. The most "correct" slopes have to make as simple basic elements as possible. therefore, the ideal angles are 0 and 90 degrees. In them, 1-pixel primary elements are joined without any shift and form even lines. Less perfect are slopes which form primary elements of 1, 2, 3 pixel with 1-pixel downshift. Surely, the lines can not be even, but the human sight will process the image and provide to the user what you meant to show to him. Also, the following angles can be considered correct (but at a stretch): slopes with basic elements made of different lines shifted by more than 1 pixel.
It is the time to touch another problem. In the last paragraph, I purposely defined slopes with primary elements of 1, 2 and 3 pixels as acceptable. Such small lines, especially when a great number of them is combined, look like a single whole. But what happens if we change the basic elements to 10 or 20 pixels?
Here is an example:
It can be obviously seen that the line doesn't have integrity. It is not a continuous line now; it is a set of several lines, situated near one another. Rarely any designer wants its creation to look that way. Thus, we come to the second conclusion: if you use minimal slopes, which produse long primary elements, it must be justified and employed with great caution.
And, finally, the third thing I wanted to tell about lines. I did write that the primary element has to be as plain as it can.
For instance, a 25-degree slope can be drawn in the two (sure more of them are possible) following ways:
In the first picture the primary element is a 2-pixel line. In the second case, it is made of three lines: 3-pixel, 2-pixel and 1-pixel. The same angle but the look is different. The complex primary element made the line untidy.
This examples can be made for almost any slope, so in your works, make sure to simplify everything.
It can be stated without an exaggeration that the color is the leading aspect of your work; improper or badly balanced colors can ruin even the best idea. What can we say about the color in icon graphics?
First, there is a clear rule: if the picture looks bad when reduced to monochrome, it means the colors that were selected are wrong. This rule is true not exclusively for icons but for the entire graphic design.
Second, you will be unable to apply safe RGB. Sure, you can use internet colors only, but this ties you hand and foot. Gradients, shadows, blending and many other effects will not be accessible to you.
Third, try to enlarge the portion of "plain" color. The more consistently colored areas without blurring and jumps your picture has, the more neat it looks. Pictograms are too small and the over usage of complex effects makes the image look messy.
Fourth, gradients. This is a wonderful tool which can improve the look of any picture. Besides esthetics, gradients are an ideal way to abolish the "broken line" look (lines with too long basic elements). But be attentive when applying them since too many gradients can kill the plain color, and be unable to fit into the gif palette.
Fifth, shadows and flares. All aspects of applying shadows and highlights in icon design are totally the same to the aspects of the overall graphic design. The only thing I would like to mention: create everything yourself. Don't apply filters, make all shadows and highlights in a separate layer and after that edit its transparency. When applying effects, you almost never can predict what the result will be. It is unfavorable when you don't control the making of a project. It is worse if you can't control it if creating miniatures.
And, lastly, sixth. Tinting is the key detail of pictogram design, which greatly affects the esthetic look of the project. If the blue human eye in the image is sized 1 pixel, increase the color intensiveness. For example, instead of 0, 131, 159 choose 71, 195, 242. It doesn't matter that the human eye can't have this color; in the first case it will look like a gray dot, and in the second case it will definitely be a green eye.
Thoroughly control the image, do not allow the visual illusions to ruin your design. It is OK if objects is not consistent technically, but the entire image must be flawless.
As an example, I drew the packet of juice standing before me. The image has flat color, gradients with broken lines, shadows and flares and tints.
If I talked about something bigger than miniature design, this part wouldn't fit into a whole book, but the resolution of pictures ;limits fonts too.
The size of symbols becomes the main issue as opposed to their beauty. Almost in all cases, unless the letters are the main part of the image, the text size must be reduced to the largest extent possible.
In principle, virtually any graphic company has its own font with tiny letters. Such a font can be created in several hours. You can search the web and collect your own collection of very nice fonts. Primarily, I would recommend you to get the DS Pixel and Seventen 7Vedi webpage and the whole set of fonts from the Lakmus Lab website.
If you don't want a new font, tiny sizes of Arial and Verdana may do. As a last resort, you can create the necessary characters by hand.
There are quite a few rules there. First, letters cannot be less than 5 pixels high or less than 3 pixels wide.
Second, letters should not use anti-aliasing. It transforms the font into an incomprehensible set of pixels.
Though, there are no rules without exceptions and the 5-point Arial looks rather understandable.