Eyebrows are the most important feature in defining the face, as they both frame and give it balance.
The trick to applying a natural eyebrow shape is using a hard stiff, short brush, and working with colorations instead of pencils.

Pencils can be used, but it takes practice and patience to get a natural look.  Tweezers are also essential to remove stray hairs and give your brows the shape you want.

How to Maintain Your Eyebrows
1. To find where your brow begins hold a pencil very carefully vertically against the side of the nose. This should line up with the beginning of the eye, the eraser nearest the nostril and the point nearest the brow. Tweeze excess hair that extends beyond the pencil over toward the nose. Excess hair towards the nose tends to make your eyes look close together.
2. Now keep the eraser end in place and move the top point toward the temple stopping diagonally at the point above the outside edge of the iris of your eye. This is where the arch of your brow should begin. Being sure not to make the brows too thin, tweeze away excess hairs beneath the arch.
3. Once again keeping the eraser in place, move the pencil point to the outside corner of the eye. This is where you want your eyebrows to stop. Tweeze hairs that extend beyond the point where the pencil meets the brow. If your eyebrows grow past that point it tends to make your eyes go down. At this stopping point it helps to lift your eyes up. The same is for the arch. The arch helps to lift and open your eyes.
Eyebrow Tips