This is how you will give your nails a perfect oval shape (VIDEO)

You will only need a thick paper file and learn the right movements to be able to give the perfect oval shape to your nails.

What you have to do is a movement from the side middle part of the nail towards its top until it takes the angle you want. Follow the same procedure on the other side of the nail and then make a semi-circular motion on the top of the nail.
It's not difficult, you just need to follow the right technique. See in the following video how to make the perfect oval shape: