Updated: Nov 3, 2020
Now this had radically changed throughout the last two decades. To achieve that fashion forward look with a well tapered pant, one option is to cut just about the ankle to show off a sock that coordinates with your ensemble.
I personally prefer a more regimented standard that abides to any choice of taper. Length is to be dictated by your back crease. Essentially Your hem will be as low on your heal as it can go before the back of your pant starts to buckle, allowing the front to have a natural buckle in it's crease. This will give you the appearance of not being too long from the back, and not too short from the front.