Let's consider strictly technical aspects of icon creation
1. Lines, slopes
One of the most important parts of the composition is the framework of the object, i.e. solid line, which limits the object from the rest of the image. When designing large-scale graphics, the artist occasionally thinks about defining objects with additional outlines. This is unnecessary because of the size: even low contrast objects do not mix into a one. Icon graphics is other story. Two variants are available: either foreground and background colors must be from different sides of the color chart, 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 return more to the big-size graphics, we can note that in order to highlight contours, we can use any (even the most complicated) angles, Bezier splines and borders. In any case, the line will look ideal due to anti-aliasing. When shrinking the graphic scale to the small icon size, situation changes greatly. When every single pixel is equally valuable and can change the whole look of the icon, anti-aliasing is just not applicable. It means that you should consider the possible line angles.
The angle you select for the line, determines the step of this line. Because each line is made of basic elements, the union of which defines its neatness and esthetics.
For example, a 18-degree slope consists of many small 3-pixel lines combined with a 1-pixel downshift:
This is how almost each line looks like. Basic element with joining and second primary element. Unfortunately, not each slope creates lines that look look neet and not annoying.
For example, here are 25 and 20-degree slopes:
It can be easily known which line is more attractive. The 25-degree slope produses a line consisting of even 2-pixel basic elements. The 20-degree angle has a primary element consisting of three parts: 3-pixel, 3-pixel and 2-pixel. The angle is more complex, thus, when not supported by other visual effects, it brings a feeling of untidiness: the basic elements have contrast which is too obvious to escape the human eye.
Now we can see the first rule. The most "appropriate" slopes must make as simple primary elements as they can. therefore, the ideal angles are 0 and 90 degrees. In those, 1-pixel primary elements are combined without downshift and form even lines. Less perfect are slopes which form basic elements of 1, 2, 3 pixel with 1-pixel downshift. Surely, the lines can not be even, but the human brain will process the picture and provide to the user what you meant to show to him. Also, the following slopes can be considered correct (but at a stretch): angles with basic elements made of unequal lines shifted by more than 1 pixel.
It is the time to move to another issue. In the previous paragraph, I purposely defined slopes with primary elements of 1, 2 and 3 pixels as acceptable. Such tiny lines, especially when a large number of them is combined, look like solid. But what happens if we increase the basic elements to 10 or 20 pixels?
Here is an example:
It can be obviously seen that the line doesn't have solidness. It is not a continuous line now; it is a set of different lines, located near each other. Hardly any artist wants its composition to look inconsistent. So, we come to another rule: if you use minimal angles, which make long primary elements, it has to be reasoned and employed with maximum caution.
And, finally, the last aspect I have to tell about lines. I already wrote that the basic element has to be as simple as it can.
For instance, a 25-degree slope can be produced in the two (of course more of them are possible) following ways:
In the first case the primary element is a 2-pixel line. In the other picture, it is made of three elements: 3-pixel, 2-pixel and 1-pixel. The same angle but the look is different. The complex basic element made the line messy.
This examples can be made for about any angle, so in your projects, make sure to simplify as much as possible.
It can be said without an exaggeration that the color is the main aspect of your work; improper or badly balanced colors can kill even the best idea. What can we write about the color in miniature graphics?
First, there is a clear rule: if the picture looks poor when converted to monochrome, then the colors that were used are incorrect. This rule is true not only for icons but for the whole graphic design.
Second, you will be unable to apply common RGB. Sure, you may select GIF colors only, but this limits you greatly. Gradients, shadows, dithering and many other tricks will not be available to you.
Third, try to enlarge the areas of "plain" color. The more consistently colored parts without diffusion and jumps your project has, the more clear it looks. Icons are too tiny and the over usage of complex effects makes the picture look messy.
Fourth, gradients. This is a great tool which can improve the appearance of any composition. Other than esthetics, gradients are an ideal way to get rid of the "broken line" look (lines with too long basic elements). But be careful when applying them since too much gradients can kill the plain color, and be not suitable for the gif palette.
Fifth, shadows and flares. All aspects of applying shades and flares in icon design are totally identical to the aspects of the overall graphic design. The only ine I have to note: draw everything yourself. Don't apply effects, make all shades and flares in a separate layer and then edit its transparency. When applying effects, you rarely know what the result will be. It is unfavorable when you don't control the making of a composition. It is worse if you can't control it when creating icons.
And, finally, sixth. Tinting is the main aspect of pictogram design, which greatly affects the visual look of the image. When the blue human eye in the picture has the size of 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 never has this color; in the first example it will appear like a gray dot, but in the second one it will really be a blue eye.
Thoroughly control the picture, do not allow the optical tricks to spoil your work. It is OK if something is not consistent technically, but the entire composition must be flawless.
As an example, I drew the pack of juice located in front of me. The image has plain color, gradients with broken lines, shadows and highlights and nuances.
If I wrote about something other than pictogram design, this chapter wouldn't fit into an entire book, but the resolution of compositions ;limits fonts too.
The size of letters is the leading aspect as opposed to their fineness. Nearly in all cases, unless the letters are the primary part of the composition, the text size has to be decreased to the greatest extent possible.
In general, virtually any graphic company has its own font with small characters. Such a font can be created in a few hours. You can browse the internet and collect your own library of very nice fonts. Primarily, I would recommend you to get the DS Pixel and Seventen 7Vedi webpage as well as the entire series of fonts from the Lakmus Lab website.
If you don't want a new font, little sizes of Arial and Verdana may do. As a last resort, you can draw 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 turns the font into an unrecognizable mixture of pixels.
However, there are no rules without exceptions and the 5-point Arial appears rather understandable.