Use a very sharp blade, lame, or razor
Score the dough just before baking
Hold the blade at a shallow angle, about 30 to 45 degrees
Make quick, confident cuts
Cut about 1/4 to 1/2 inch deep
Score one main slash for a loaf, or multiple cuts for a pattern
Keep the cuts clean and smooth
Avoid dragging the blade through the dough
Dust the dough lightly with flour if needed for visibility
Score in a way that directs oven spring where you want it to open
Work fast so the dough does not deflate
Use a firm surface and steady hand
Practice simple patterns before trying decorative designs