You can use this method for any type of potato and preparation: cubes, fries, wedges, slices, or whole small potatoes (like new potatoes or fingerlings). Just keep in mind that the blanching time will depend on the size of your potatoes.
First, scrub the potatoes clean. I prefer to leave the skin on potatoes, but you can peel them if desired. Cut them into your desired size and shape.
Bring a large pot of water to a boil. In the meantime, fill a mixing bowl with ice water. Alternatively, you can set up a colander in the sink to rinse the potatoes with very cold running water if you don't want to submerge them into ice water.
When the water is boiling, transfer the potatoes to the pot. Blanch cubes and thin slices of potatoes for 3 minutes and fries, wedges, and other larger pieces of potato for 5 minutes.
As soon as your timer goes off, remove the potatoes from heat and transfer them to the bowl of ice water using a slotted spoon. The ice water will stop the cooking process. Alternatively, drain the potatoes immediately into a colander. Rinse under cold running water for 30 seconds to stop the cooking process.
If using the bowl of ice water, drain the potatoes. Pat them dry. Spread out in a single layer on a lined baking sheet.
Place the baking sheet in the freezer, somewhere it won't get bumped. Freeze the potatoes for about an hour or until frozen solid.
Transfer the flash frozen potatoes to freezer bags or containers. Seal tightly, removing as much air as possible. Label.
Store in the freezer for up to 6 months.