Let's discuss strictly technical details of icon creation
1. Lines, slopes
One of the most important elements of the composition is the outline of the object, i.e. solid line, which separates the object from the rest of the image. When creating normal-sized graphics, the designer occasionally thinks about defining objects with complementary outlines. This is unnecessary because of the size: even non-contrasted objects do not blur into a single whole. Pixel graphics is different. Two variants are possible: either foreground and background colors must be from opposite sides of the color wheel, or the object should be separated from the background by contrast outlines and shadows. I would like to dwell on lines deeper.
If we think more to the big-size images, we see that in order to define contours, we can use all (even the most complex) angles, Bezier curves and edges. Anyway, the line will appear perfect thanks to anti-aliasing. When shrinking the graphic scale to the small icon size, situation changes greatly. When each particular pixel is vitally important and can ruin the overall appearance of the composition, anti-aliasing is just not applicable. It comes that you should think about the possible line slopes.
The slope you choose for the line, determines the step of this line. This means that each line is made of primary elements, the combination of which defines its neatness and visual appeal.
For instance, a 18-degree slope consists of many tiny 3-pixel lines combined with a 1-pixel downshift:
This is how nearly each line looks like. Primary element followed by joining followed by another primary element. Unfortunately, not each angle creates lines that look look neet and not messy.
For example, look at 25 and 20-degree slopes:
It can be easily seen which line is more appealing. The 25-degree angle makes a line containing equal 2-pixel basic elements. The 20-degree slope has a primary element consisting of three parts: 3-pixel, 3-pixel and 2-pixel. The angle is more complicated, therefore, if not supported by other visual effects, it creates a feeling of untidiness: the basic elements have contrast which is too obvious to escape the human sight.
Here we can come to the first conclusion. The most "correct" slopes must make as plain basic elements as possible. therefore, the ideal angles are 0 and 90 degrees. In them, 1-pixel basic elements are combined without downshift and produce smooth lines. Less perfect are slopes which form basic elements of 1, 2, 3 pixel with 1-pixel downshift. Of course, the lines can not be even, but the human brain will process the picture and present to the viewer what you intended to show to him. Also, the following slopes can be considered acceptable (but at a stretch): angles with primary elements consisting of unequal 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 primary elements of 1, 2 and 3 pixels as correct. Such small lines, especially when a large number of them is joined, look like a single whole. But what do we see if we change the primary elements to 10 or 20 pixels?
Here is an example:
It can be clearly seen that the line doesn't have integrity. It is not a single line now; it is a set of different lines, located near one another. Rarely any designer wants its creation to look that way. Thus, we have another conclusion: if you use minimal slopes, which produse long basic elements, it has to be reasoned and used with maximum attention.
And, finally, the last thing I have to tell about lines. I did write that the primary element should be as plain as possible.
For example, a 25-degree angle can be produced in the two (sure more of them are possible) following ways:
In the first case the primary element is a 2-pixel line. In the other picture, it consists of three lines: 3-pixel, 2-pixel and 1-pixel. The same slope but the image is different. The complex primary element made the line untidy.
Such examples can be made for almost any slope, so in your projects, make sure to simplify everything.
It can be said without an overstatement that the color is the leading aspect of your work; improper or poorly matched colors can ruin even the best idea. What can we say about the color in miniature graphics?
First, there is a clear rule: if the image looks poor when converted to grayscale, then the colors that were selected are incorrect. This rule is true not exclusively for icons but for the whole graphic design.
Second, you will be unable to use common RGB. Sure, you may select internet colors only, but this limits you greatly. Gradients, shadows, dithering and many other tricks will not be available to you.
Third, try to increase the portion of "plain" color. The more evenly colored areas without blurring and jumps your project has, the more neat it looks. Icons are too small and the excess usage of special filters makes the image look dirty.
Fourth, gradients. This is a great tool which can change the look of any composition. Other than visuals, gradients are a perfect way to get rid of the "broken line" effect (lines with too long primary elements). But be attentive when applying them since too much 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 making are totally the same to the rules of the general graphic design. The only thing I have to note: create everything by hand. Don't apply effects, make all shadows and flares in a separate layer and then edit the opacity. When using filters, you rarely 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 when drawing icons.
And, lastly, sixth. Nuancing is the key aspect of icon design, which largely results the esthetic look of the project. If the green human eye in the icon is sized 1 pixel, increase the color intensiveness. For example, instead of 0, 131, 159 make 71, 195, 242. It is indifferent that the human eye never has such color; in the first example it will look like a gray dot, and in the second case it will definitely be a green eye.
Thoroughly control the picture, do not let the visual tricks to spoil your design. It is OK if something is not consistent from the technical point of view, but the whole composition must be perfect.
As an example, I drew the packet of juice located before me. The image has flat color, gradients with broken lines, shades and flares and tints.
If I talked about something other than miniature design, this chapter wouldn't fit into a whole book, but the resolution of pictures restricts fonts too.
The resolution of letters becomes the leading issue as opposed to their beauty. Almost in all cases, only if not the letters are the primary part of the image, the font size has to be reduced to the largest extent possible.
In general, almost any design company has its unique font with little characters. Such a font can be created in a couple of hours. You can search the internet and make your own library of very nice fonts. First of all, I advice you to download 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, small sizes of Arial and Verdana may work. As a last option, you can create the needed characters by hand.
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 transforms the text into an unrecognizable set of pixels.
However, there are no rules without exceptions and the 5-point Arial appears perfectly understandable.