Let's discuss strictly technical details of icon creation
1. Lines, angles
One of the most important elements of the composition is the framework of the object, i.e. rough linear marking, which separates the object from the rest of the image. When working with large-scale graphics, the designer rarely thinks about defining objects with additional lines. This is not needed because of the scale: even low contrast objects do not blur into a one. Pixel graphics is different. Two variants are available: either object and background colors have to be from opposite sides of the color wheel, or the foreground must be divided from the background by contrast outlines and shadows. I will discuss lines in more detail.
If we return again to the big-size graphics, we can note that in order to define edges, we can use all (including the most complex) angles, Bezier curves and borders. In any case, the line will look perfect thanks to anti-aliasing. When shrinking the graphic scale to the small icon size, situation changes dramatically. When each particular pixel is equally valuable and can ruin the overall appearance of the icon, anti-aliasing is just unreasonable. It means that you have to think about the possible line angles.
The slope you select for the line, determines the step of this line. Because each line is made of primary elements, the union of which defines its neatness and esthetics.
For instance, a 18-degree slope contains many small 3-pixel lines connected using a 1-pixel downshift:
This is how almost each line looks like. Basic element followed by joining and second primary element. However, not each angle makes the line look attractive and not messy.
For example, look at 25 and 20-degree angles:
It can be easily known which line is more appealing. The 25-degree angle produses a line consisting of equal 2-pixel primary elements. The 20-degree slope has a basic element consisting of three lines: 3-pixel, 3-pixel and 2-pixel. The slope is more complex, therefore, when not combined by other visual effects, it creates a feeling of messiness: the primary elements have contrast which is too obvious to escape the human sight.
Now we can see the first rule. The most "correct" slopes must make as simple primary elements as they can. Thus, the ideal slopes are 0 and 90 degrees. In those, 1-pixel basic elements are combined without any shift and produce even lines. Less ideal are angles which form basic elements of 1, 2, 3 pixel with 1-pixel downshift. Of course, the lines can not be smooth, but the human sight will process the picture and present to the user what you meant to show to him. Also, the mentioned slopes can be considered correct (but at a stretch): slopes with primary elements consisting of different lines shifted by more than 1 pixel.
Now we can discuss another problem. In the previous paragraph, I purposely defined slopes with basic elements of 1, 2 and 3 pixels as correct. Such small lines, especially when a great number of them is joined, look like solid. But what do we see if we increase the basic elements to 10 or 20 pixels?
Here is an example:
It can be clearly noticed that the line loses its integrity. It is not a continuous line anymore; it is a combination of different lines, located near each other. Hardly any designer wants its creation to look that way. So, we have another rule: if you use small angles, which make long primary elements, it has to be justified and used with maximum attention.
And, finally, the third thing I have to tell about lines. I already wrote that the basic element has to be as plain as it can.
For example, a 25-degree angle can be drawn in the two (sure more of them exists) 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 produced the line messy.
This examples can be made for almost any slope, so in your projects, try to simplify everything.
It can be stated without an exaggeration that the color is the leading element of your work; improper or badly matched colors can ruin even the best idea. What can we write about the color in icon graphics?
First, there is a clear rule: if the picture looks bad when reduced to monochrome, then the colors that were selected are incorrect. This rule is valid not exclusively for icons but for the entire graphic design.
Second, you will be unable to apply safe RGB. Sure, you may use GIF colors only, but this ties you hand and foot. Gradients, shadows, dithering and many other effects will not be available to you.
Third, try to increase the areas of "flat" color. The more evenly colored parts without blurring and jumps your composition has, the more neat it appears. Icons are too tiny and the over usage of complex effects makes the image look dirty.
Fourth, gradients. This is a wonderful instrument which can improve the appearance of any project. Besides esthetics, gradients are an ideal way to abolish the "broken line" effect (lines with too long basic elements). But be careful when applying them since too many gradients can kill the flat color, and be unable to fit into the gif palette.
Fifth, shadows and highlights. All rules for applying shades and highlights in icon making are completely the same to the aspects of the general graphic design. The only ine I would like to mention: create everything yourself. Don't apply filters, make all shades and flares in a separate layer and after that edit its transparency. When applying filters, you rarely can predict what the result will be. It is bad when you don't control the process of creating of a project. It is worse if you don't control it if drawing miniatures.
And, finally, sixth. Tinting is the main detail of icon creation, which largely results the esthetic look of the image. If the green human eye in the image has the size of 1 pixel, increase the color intensiveness. For example, instead of 0, 131, 159 make 71, 195, 242. It doesn't matter that the human eye never has this color; in the first case it will look like a gray dot, and in the second one it will definitely be a green eye.
completely control the image, do not allow the visual tricks to ruin your work. It is OK if objects is not consistent technically, but the whole picture must be perfect.
As an example, I pictured the packet of juice standing in front of me. The image has flat color, gradients with broken lines, shadows and flares and nuances.
If I wrote about something other than miniature creation, this chapter wouldn't fit into a whole book, but the resolution of images restricts fonts too.
The size of symbols becomes the main aspect as opposed to their fineness. Nearly in any case, unless the letters are the main part of the project, the font size must be decreased to the largest extent possible.
In principle, virtually any design company has its exclusive font with tiny letters. This font can be crafted in several hours. You can browse the web and collect your own collection of very interesting fonts. Primarily, I would recommend you to download the DS Pixel and Seventen 7Vedi webpage and the complete series of fonts from the Lakmus Lab website.
If you don't need a new font, small typesizes of Arial and Verdana will do. As a last resort, you can draw the needed characters yourself.
There are not many rules there. First, characters cannot be less than 5 pixels high or less than 3 pixels wide.
Second, letters cannot use anti-aliasing. It turns the text into an incomprehensible mixture of pixels.
However, there are no rules without exceptions and the 5-point Arial looks rather readable.