First, you can’t just rinse off the curing spices and start slicing away. The fish will be too wet, and the pieces will fall apart. Instead, give your fish a little refrigerator time: Just four hours (loosely covered) is enough to firm up the flesh for better results. A sharp, thin, flexible slicing knife is also key. Start five inches from the tapered end of the fish and—keeping the blade parallel to the counter—slice “sheets” of salmon, using a gentle sawing motion as you glide your knife along. The pieces should be so thin that you can see the knife through the fish. Your first few pieces won’t be perfect, but it gets easier as you go.