Start by mixing the salt, sugar, and coarsely chopped dill in a bowl using a spoon or your fingers.
Lay out a long sheet of plastic wrap on your counter (long enough to fit the piece of salmon and go around it a couple times).
Put half of the salt/sugar/dill mixture on top of the plastic wrap. Spread it out in a thick layer that's approximately the size of the salmon fillet.
Lay the salmon on top of the salt mixture, skin side down.
Cover the top of the salmon with the remaining salt/sugar mixture, packing it down as tightly as possible.
Wrap the fish completely and as tightly as possible in the plastic wrap, all the way around (you can even do a couple of layers to make sure it's completely wrapped up).
Place the salmon in a large tray or baking dish. Put some heavy weights on top of it (I usually use 3 or 4 cans of beans or tomato sauce).
Place the salmon in the fridge and flip it every 12 hours for anywhere between 36 to 48 hours. You can even go up to 3 days if you like the salmon to be very cured.
When you're done curing it, unwrap the salmon from the plastic wrap, scrape off all of the salt, and dry it with a paper towel. Place the cleaned, cured salmon on a plate and return it to the fridge for a couple of hours before slicing and serving.