The basics for gravlax are 50/50 sugar and salt, dill and coarse pepper either white or black. Some people like to add slightly more sugar and some a little more salt. Make sure there is enough to rub it in both sides of the salmon and to sprinke a layer on top, if there are two filets or pieces. Mix the salt and sugar and rub it in the salmon good, add a little pepper and spread fresh dill on top(dried dill works too) if you have two filets put them together - skinny side out - and sprinkle some more of the salt/sugar mix and some more dill on top. Cover with plastic film or put in a sealed plastic bag. Let stand in the fridge for 2-3 days (depending on the thickness of the filet). There is no harm in leaving the salmon to marinate up to 5 days. Just make sure your fridge stays cold enough. Turn the filets each day so they can marinate evenly. If the files are thick, put some weight on the thickest part.Gravlax, however, gives plenty of choices to follow your own preference of flavors. Instead of dill one can use other herbs or herb mixes, add a little sprinkle of your favorite liquer such as Drambuie or Cointreau. Even flavored vodkas can add a very good touch. Lemon and lime are often used for flavor, but remember to cut the skin (all the white stuff or use just the zest) off first. Have fun with it.
Serving options are also plenty. Just the gravlax served as is with some hovmästarsås is good for an appetizer, but it is also very good lightly grilled or in salads. A gratin with gravlax is excellent. One can toast it on bread with mustard sauce. These were just some suggestions for alternative uses of Gravlax.
Good luck and Bon Appetit!