The standard rules to get perfect eyebrows for your face shape are
Start directly up from the edge of your nose and draw the line on the eyebrow.
Your eyebrow should end in line with the corner of your nose and the outer corner of your eye
Your brow arch should be in line with the outer edge of your nose.
Start your eyebrow at your desired nose bridge width. This will give the false impression of a thinner nose.
Straighter brow is more youthful and more stylish. An over arched brow creates a puffy eyelid so keep it straight to give the false impression of a thinner face.
The most important thing to remember is to follow your natural shape as this is usually the perfect brow for your face shape.