This is how our grandmother made it and this is how we still do it.
Mix the vinegar well in a bowl with sugar, salt, pepper and dill. Peel the cucumber and slice it into wafer-thin slices, add to the dressing with the juice, let it steep for about an hour, then season again to taste. If the cucumber gives off a lot of juice, don`t add all of it.
The balance between juice and vinegar is important. Since one cucumber is not enough for four people with us, I specified 3, of course it can also be enough for four.