Write an article based on this "Download a crosshair generator online. Customize your crosshairs from within the map. Generate a custom crosshair and paste the code into the developer console."
One of the most popular is available on the steam workshop. It is a map by CrashZ called "Crosshair Generator." You can also search for "CSGO Crosshair Generator" using your favorite search engine. Opening the map will allow you to change the size of your crosshairs and will give you tons of different options to customize with color, gap, dot, and so on. You can also check your crosshairs against a variety of backgrounds to make sure it is visible. The CrashZ map allows you to select crosshairs used by professional Counter Strike players, so you can make like the pros. Other crosshair generators will allow you to tinker with your settings and, once it's perfect, gives you a code with all your customizations. Copy this code, then open the developer console in Counter Strike and paste the code into the box. Your crosshairs will change to match the version you made in the generator.