I think the trick is to touch up knives that are only slightly dull, keeping them razor sharp, then work your way to slightly duller and then duller knives to get the hang of it. Don't bare down on the blade when stroking/"slicing" on touch-ups, just wet the stone and use a low angle to the stone, about the width of the blade itself. This will help you get the feel for sharpening. When you get a factory edge, if you hold it right to the light (looking from the side) you will notice a very thin line of light at the edge, this line is what you want to reproduce and it's easier to do that on touch-ups.
If you look straight on to a blade, that is the narrow part, you can see a reflection of light if it is dull (you will see dull spots or sections). This is different from the line I'm talking about when looking at the blade from the side.