Place the cucumber slices in a bowl. Mix one tablespoon of salt with the water and stir until the salt is dissolved. Pour the salt water over the cucumber slices, cover, and let them sit for 2-3 hours. Drain the cucumbers and discard the salt water.
On the stovetop, combine the apple cider vinegar, white vinegar, water, sugar, and salt. Cover the pot and bring the mixture to a simmer until the sugar and salt are dissolved. Remove from heat and set aside.
In the bottom of each pint mason jar, add 1/2 teaspoon of dill seed, 1/4 teaspoon of pickling spices, and 1/2 teaspoon each of minced garlic and dried minced onion. Divide the cucumber slices among the jars.
Carefully use a funnel to pour the vinegar mixture over the cucumber slices, leaving about 1/2-inch of space between the pickles and the top of the jar. Wipe the rims of the jars with a clean damp cloth or paper towel. Place a lid on each jar and tighten securely.
Allow the jars to sit for 3 weeks before opening.
The pickles can be stored in the refrigerator for up to three months. Alternatively, you can use the water bath canning method for preservation. Properly canned pickles are good for up to a year as long as sealed properly. Store in a cool, dry place.