I use a fine diamond wheel, and grind by feel. Then I look at what I did. If it doesn't look right, I grind it again. I try to make the flutes even height, hold up to the light, make sure the lips are at the same height, same angle, and the point is in the center of the bit. Of course, while doing this, you must have the right back rake.
Those little drills are hard to sharpen successfully. They also wear on the diameter pretty fast, so when you grind, take a good amount off so you get the worn end off.
If you sharpen large bits OK, then it's the same motion, only the bits are smaller. So scale down your motions and use a fine wheel, and you may be surprised that you can actually sharpen what you thought was impossible.
Good Luck!
Tom