Ah, the infamous cat eye. Classic, and ultra feminine, and really all you need if you need to finish off a look, especially if you are not a lipstick kind of woman. It is not easy to perfect; you have to play around each time. One eye always turns out better then the other, then the trick becomes making the one eye look like the other. Cat eyes need to be sisters, they are not close cousins like the eyebrows.
The wand or the pen is great for beginners because it gives you more control. Although I am still a novice I find I have more control with a brush. I have recently opted for the right brush and the Make-Up Forever eyeliner pot. I like it because it is matte and I find with the right brush you can play around with the angles and the line thickness more so then with the pen.
A makeup artist also taught me little trick, she told me to take a business card, lay it flush to the cheek bone on your lower eyelid following your eye line, angle it up toward your temple and then draw in that perfect straight line. After this initial first step you then move from the outer edge to the inner. So it is essentially the above but in reverse. It is a clever little trick and it works well. With enough practice you may no longer need the business card. It's all in the wrist, and sometimes in the mood.