Use a Sharpie to see where the stone (I'm assuming you're using a bench stone of some sort) is grinding the edge. As you push the edge across the stone, you'll have to elevate your hand to maintain the same bevel angle when it curves toward the tip. How much you need to elevate will depend on how much of a curve (belly) your particular knife has - generally the larger the curve, the higher you'll have to go. Use the Sharpie and you'll be able to see if you're grinding all the way to the tip and how consistent you're holding the angle. It's not easy, as you get to the tip there'll be less feedback from the stone as there'll be less steel contacting it for reference. You'll feel if it begins to catch on the stone = you've elevated too high. Too much grinding on the shoulder = too low.
HH