Vincent
The idea to anticipate might be good, but its often the main cause to over control. The squares are coming towards you (or you are travelling towards the squares) at quite a low speed, so I think there are more than enough time to see where its moving, before you start putting in little adjustment to the aircraft's flight path. When you start, there is quite a distance before you get to the first box, so you should start getting yourself setup at the correct imaginary flight path as early as possible, so by the time when you reach the first box, you are going in smooth and already lined up for the next few boxes, therefore minimal corrections are needed.