Wash and slice the cucumbers into rounds or spears as desired, and set them aside.

In a medium saucepan, combine the water, white vinegar, salt, and sugar. Heat the mixture over medium heat, stirring until the sugar and salt dissolve completely. Remove from heat and let it cool slightly.

In a clean glass jar or container, layer the cucumber slices with the garlic slices, fresh dill, black peppercorns, and mustard seeds.

Pour the slightly cooled vinegar mixture over the cucumbers, ensuring they are completely submerged.

Seal the jar tightly and refrigerate for at least 24 hours to allow the flavors to develop. For best results, let the pickles sit for 48 hours before serving.