It takes so much practice, especially when it comes to utilizing a mirror to see the back of your head on ANOTHER mirror.
I have now hit day 15, and I am still holding strong, though it is starting to become hard to maintain the sharpness my barber perfects with the liners. It still looks acceptable and way, way better than if I had done nothing, but it has definitely reached a point where I don't look like I just got out of the barber chair anymore.