In February get good organic seed potatoes and teat them to a little tender loving care. By placing them in eg boxes in a light (but not directly sunny) spot where the temperature stays around 10 degrees (a conservatory is perfect) you can let them send up loads of green shoots. In a month’s time plant these out and your potatoes will have had an excellent head start.
This is particularly good for early varieties such as Accent, Duke of York, Arran Pilot or my favourite, Pentlan Javelin. However it will also benefit second early and maincrop potatoes too.