Beat a defender with the body, not the feet. Sell the fake by dropping the shoulder and leaning hard one way, then push the ball the opposite way with the outside of the foot and burst past into space.
From a start cone, dribble at a defender (a mannequin or cone), keeping the ball close. A step or two away, slow down, drop your shoulder and lean hard to one side, then push the ball the other way with the outside of your foot and accelerate to a finish cone. The ball stays close through the fake, the deception is all in the body. Ten reps each way, both feet.
Every skill move a player will ever learn rests on one idea, and the body feint is that idea with everything else stripped away. During the fake the ball does not move at all. Only the body does. That is what makes it the right first move to teach and the reason it keeps working at every level afterwards.
A defender does not react to the ball. He reacts to your hips and shoulders, because those are what tell him where you are about to go. Once a young player understands that, every other move becomes easier, because the foot part of a step-over or a chop is decoration hung on the same principle. Teach this one badly and everything built on it wobbles.
The fault to watch for is a big touch during the feint. Players who are used to moves involving the ball will instinctively push it one way to sell the lie, which is exactly wrong here. The ball stays under the body, and if it drifts even half a yard the defender simply takes it, because for that moment nothing is protecting it.
The second fault is going too fast. Approaching at full speed leaves no time for the defender to register the fake and shift his weight, so the lean does nothing and the player runs into a defender who never moved. Slow slightly on approach, freeze him, then accelerate. The change of pace is doing as much work as the feint.
Save it to your private drills, then change the animation, adjust positions, swap equipment, or drop it into a session block. Or start from a blank pitch and build your own.