Dashicons are the icons used throughout the WordPress admin. There are several reasons why you might want to design Dashicons. Maybe you’re an icon designer, and want to contribute to WordPress. Or you want to design a custom icon for a plugin.
If you want do make Dashicons, following these guidelines will help ensure that they look and function great.
They should be simple. Consider extraneous details within the icon. Are they really necessary?
They should be universal. Are your own demographics influencing the symbol you’ve chosen for the icon?
They should be consistent. Examine your icon in context. How would it look in the wp-admin environment?
While the icons should be as clear as possible, Dashicons are also friendly and reassuring. Slightly rounded edges are encouraged over sharp, 90º angles. Try a squircle. When given the choice, angle them to the right; e.g., the “Tools” icon starts off on the lower-left and angles to the upper-right of the canvas.