On the Slant, 2 things to watch out for: blade alignment and proper angle to face. On blade alignment, read this thread: http://badgerandblade.com/vb/showthread.php?t=21077
Also, note that the top is flat, with two flat sloping sides. The side should be flat to your face to get the proper angle on the blade.
Although blade angle is an important factor in general, I believe this concept does not apply to the Slant. The blade angle varies along the blade edge. Therefore, there is no way one can maintain a "correct" angle. A correct angle might be achieved for a couple of millimeters of edge, but the rest will have angles that are either too shallow or too steep. Best - MM