Make sure when your sanding your flats you have a hard backing. Steel is best. If there is any give it'll washout or blur the crisp grind line. Also, the higher up the blade you go with your bevel or the thinner the stock, the more pronounced waves or bluring will be as the angle between the flat and bevel becomes less. A clean straight saber line is hard to get on thin stock. At least it is my my limited abilities anyways.
That being said, your lines look pretty good as is. You could maybe bring the grind up at the tip a little and the bevel is getting narrower.