Two main ways. Web Designer Knowledge Base
Now there are a bunch of paid and free programs and services that allow you to create prototypes of sites. At the exit, you can get a page that is almost ready - everything clicks, the menus open, the text is entered, and so on. But I believe that prototypes that are drawn by the designer “by hand” bring more benefit. Drawing a sketch with a pencil, you get much greater freedom of action. Your hands create something that is not limited by the scope of the program, and often some kind of visual solution can come precisely due to the motor skills of the hands. You probably noticed that many people like to talk on the phone and draw something on a piece of paper. They do this completely meaninglessly, and they get absolutely unprincipled drawings - but they can be beautiful, they can be interesting. They can be - oh, horror - creative! And if you do the same thing meaningfully, you get an even stronger result. Moreover, it is not necessary to have serious artistic skills and draw a prototype along the ruler (if this is not discussed with the client). But just to take and draw by hand how the site might look will be very useful. In general, if you do not push yourself into the framework of programs for prototyping, then the sketch - and in the future the site - will turn out to be less template. Another argument for pencil sketches is that they allow you to find solutions not only by layout, but also by style, by some graphic ideas on the site. Roughly speaking, at this stage I can already put in the site design the style of buttons with rounded corners. Or angular information blocks in the style of Windows 8. Or a picture embedded under some element of the site. Drawing with a pencil, at the same time, you can do more useful work and immediately determine for yourself and the customer more important things.