A fade is something that alot of barbers have trouble with at first because it just takes alot of practice. The easiest way to do a fade is to “fade down.” Start with a larger guard or blade first. Heres an example. Say the person you’re giving a haircut tells you he wants a 5 guard on the top, faded with a 2 guard on the back and sides. (some clipper guards are different, but in most cases the larger the number, less hair it takes off)

Start with the 5 blade. Take it over the entire top of the head and down the sides past the round of the head. After you have done this, take the 4 guard and start on the sides and go straight up with the clippers. When you reach the point where the hair was cut to the 5 guard, move the clippers in an outward scooping motion. Continue with the other side and the back, and then repeat again, scooping into the 4 with the 3 guard, then the 2 guard.

Using this method, there should be minimal lines. If there are lines, go back over the area with a LARGER guard than you used the first time, and finish up with the thinning shears over any unblended area if neccesary.

This is very hard to describe, but hopefully with practice you will understand it more and more. Good luck!