Let's discuss strictly technical details of icon creation
1. Lines, angles
One of the vital parts of the image is the outline of the object, i.e. solid border, which limits the object from the background. When creating normal-sized graphics, the artist rarely cares about highlighting of objects with additional lines. This is not needed because of the size: even low contrast objects do not blend into a one. Pixel graphics is different. Two solutions are available: either object and background colors must be from different sides of the color wheel, or the foreground must be divided from the background by contrast outlines and shadows. I will dwell on lines deeper.
If we think more to the large scale images, we can note that in order to define contours, we can use any (including the most complicated) angles, Bezier splines and borders. Anyway, the line will appear ideal thanks to anti-aliasing. When shrinking the graphic dimensions to the small icon size, situation changes dramatically. When each single pixel is equally valuable and can change the whole appearance of the composition, anti-aliasing is just not applicable. It means that you should consider the possible line slopes.
The slope you choose for the line, specifies the step for this line. This means that each line is made of basic elements, the combination of which defines its neatness and esthetics.
For instance, a 18-degree angle consists of many tiny 3-pixel lines combined with a 1-pixel downshift:
This is how nearly every line looks like. Basic element followed by joining followed by second basic element. Unfortunately, not each angle creates lines that look look neet and not annoying.
For example, look at 25 and 20-degree slopes:
It can be easily seen which line is more appealing. The 25-degree slope makes a line consisting of equal 2-pixel basic elements. The 20-degree slope has a basic element consisting of three lines: 3-pixel, 3-pixel and 2-pixel. The slope is more complicated, thus, when not combined 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 "appropriate" slopes must make as plain basic elements as they can. Thus, the ideal slopes are 0 and 90 degrees. In them, 1-pixel primary elements are combined without downshift and produce smooth lines. Less perfect 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 viewer what you intended to show to him. Also, the following slopes can be considered correct (but at a stretch): angles with primary elements made of different lines shifted by more than 1 pixel.
It is the time to move to another issue. In the last paragraph, I purposely defined slopes with basic elements of 1, 2 and 3 pixels as correct. Such tiny lines, especially when a large number of them is combined, look like a single whole. But what do we see if we increase the primary elements to 10 or 20 pixels?
Here is an example:
It can be clearly seen that the line loses its integrity. It is not a continuous line now; it is a combination of different lines, situated near one another. Hardly any designer wants its creation to look that way. So, we come to another rule: if you use minimal angles, which make long primary elements, it has to be reasoned and used with maximum caution.
And, finally, the third thing I wanted to mention about lines. I already wrote that the primary element has to be as plain as it can.
For example, a 25-degree slope can be produced in the two (of course more of them are possible) following ways:
In the first case the basic 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 complicated basic element made the line messy.
Such examples can be produced for almost any slope, so in your projects, try to simplify as much as possible.
It can be stated without an overstatement that the color is the main aspect of your work; not suiting or badly balanced colors can ruin even the most creative idea. What can we say about the color in miniature graphics?
First, there is a certain rule: if the image looks bad when converted to monochrome, then 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 use common RGB. Of course, you can 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 "plain" color. The more consistently colored parts without blurring and jumps your composition has, the more clear it appears. Pictograms are too tiny and the over usage of special effects makes the picture look messy.
Fourth, gradients. This is a great instrument which can change the appearance of any project. Other than visuals, gradients are an ideal solution to abolish the "broken line" effect (lines with too long primary elements). But be careful 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 rules for applying shadows and highlights in icon making are completely the same to the aspects of the general graphic design. The only ine I have to note: create everything by hand. Don't use filters, make all shadows and flares in a separate layer and then edit its transparency. When using filters, you almost never know what will it look like. It is unfavorable when you can't control the process of creating of a project. It is awful if you can't control it if drawing miniatures.
And, lastly, sixth. Tinting is the main detail of pictogram creation, which greatly results the visual look of the project. If the blue human eye in the image has the size of 1 pixel, increase the color saturation. For example, instead of 0, 131, 159 choose 71, 195, 242. It doesn't matter that the human eye never has such color; in the first case it will look like a gray dot, but in the second one it will really be a blue eye.
Thoroughly control the image, do not let the optical illusions to ruin your design. It is OK if objects is not consistent from the technical point of view, but the whole image must be perfect.
As an example, I pictured the pack of juice located in front of me. The picture has flat color, gradients with broken lines, shadows and flares and tints.
If I talked about something other than miniature design, this part wouldn't fit into an entire book, but the resolution of pictures ;limits fonts too.
The resolution of letters becomes the main aspect as opposed to their beauty. Almost in all cases, only if not the letters are the main part of the composition, the font size must be decreased to the greatest extent possible.
In principle, almost any design company has its unique font with small letters. This font can be crafted in a couple of hours. You can browse the internet and collect your own collection of very interesting fonts. First of all, I would recommend you to get the DS Pixel and Seventen 7Vedi website as well as the entire series 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 draw the needed characters yourself.
There are quite a few rules there. First, letters 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.
Though, there are no rules without exceptions and the 5-point Arial appears perfectly readable.