Step One

In this tutorial, we will use the image below and make the girl invisible. I got this picture from here. You may download it from there if you must. (Thank you very much, PorcelainStock.)

Step Two

Take the Clone Stamp Tool (S). We will use only this tool to make the girl disappear! The Clone Stamp Tool usually takes a sample of the part of the image and apply it over on another part.

Step Three

Choose a brush size. I used 28px for this tutorial considering the image size was 533x773. But the size is totally up to you.

Step Four

In this step, you will make the girl's face disappear. To do so, Alt+Click on the red area spotted below. We clicked on that area because, we are going to overlay her face with that wooden black fence. So that it looks as if she is not there.

Step Five

Subsequently, drag your mouse over the part (the face) which you want make disappear and paint it. Repeat this process on any unwanted part of the image. Here's my final result.