Begin by washing and peeling the russet potatoes. Using a sharp knife or a mandolin slicer, carefully slice the potatoes into thin, uniform rounds. Place the slices in a bowl of cold water as you work to prevent them from browning.
In a large, deep pot, heat enough vegetable oil to submerge the potato slices to 350°F (175°C). Use a thermometer to maintain the proper oil temperature.
While the oil is heating, carefully pat the potato slices dry with a clean kitchen towel or paper towels. Any excess moisture can cause the hot oil to splatter.
Once the oil is at the correct temperature, carefully add a handful of potato slices to the hot oil, making sure not to overcrowd the pot. Fry them for about 2-3 minutes, or until they turn golden brown and crisp.
Use a slotted spoon or a wire mesh strainer to remove the chips from the oil and place them on a plate lined with paper towels to drain. Immediately sprinkle with salt and any optional seasonings while they are still hot.
Continue frying the remaining potato slices in batches, maintaining the oil temperature.
Allow the homemade potato chips to cool for a few minutes before serving. They will become even crispier as they cool.