Wash the cucumbers thoroughly. Slice them into thin rounds or spears, depending on your preference.
In a large mixing bowl, combine the minced garlic, white vinegar, water, sugar, salt, fresh dill, black pepper, and red pepper flakes (if using). Whisk the mixture together until the sugar and salt are fully dissolved.
Add the sliced cucumbers to the bowl, tossing them gently in the garlic dill mixture until they are evenly coated.
Transfer the cucumbers and the marinade into a clean glass jar or airtight container. Ensure that the cucumbers are fully submerged in the liquid. If needed, press down gently to pack them in.
Seal the jar or container tightly and place it in the refrigerator. Let the cucumbers marinate for at least 2 hours to develop flavor. For extra tang, allow them to sit overnight.
Serve chilled as a refreshing side dish or snack.