Lisa,
It's a combination of skill and art. I'm writing this from the
perspective of a woodworker and bread baker.
The 2 keys are: 1. visualization (the art) and 2. let the knife (saw)
do the work (the skill). It is like cutting a board with a saw, being
careful to follow the line while letting the saw do the cutting
without adding undo force. Same with a bread knife. As I watch
people cut bread, they often apply too much pressure to the knife
rather than letting the weight and teeth of the knife do the cutting.
It might take 5 strokes to penetrate the top crust. Take long slow
strokes while watching the loaf. Don't watch the knife, watch the
loaf. And don't be in a hurry.
Dr. G.