Wash the cucumbers well. Trim a thin slice off both ends – this removes the enzymes that cause softening. Cut into spears (quarter lengthwise for medium cucumbers, sixths for fat ones).
Layer dill, garlic, spices, and cucumber spears in a clean 1-quart wide-mouth jar. Pack them in tightly – they'll settle as the brine works. Dill fronds visible against the glass make for a beautiful jar.
Combine vinegar, water, salt, and sugar in a small saucepan. Bring to a boil, stirring until salt and sugar dissolve. Remove from heat.
Pour the hot brine over the cucumbers, leaving about ½ inch headspace. Tap the jar gently on the counter to release air bubbles. Add a few more dill sprigs on top if desired.
If you have a glass fermentation weight, use it to keep everything submerged. Otherwise, press the lid on tight. The top pickles might float – flip the jar every few hours for the first day to redistribute.
Leave at room temperature for a few hours (or overnight if your kitchen is cool), then refrigerate. The flavor develops best after 24 hours, but you can sneak a spear at hour 12.