Chop gherkins, capers, dill, parsley and make the mayo if necessary.
Mix all the ingredients into the mayonnaise. Don't forget the parsley and lemon juice either.
Taste it and add salt if necessary. Mind that the flavors need some time to develop but don't shy away adding more of ingredients that we like best. Fill the tartar sauce into an airtight container and put it in the fridge. As everything else with raw eggs and fresh herbs, mind not to use it over 6 days. Store bought mayo may live a bit longer though.