Add plenty of well rotted manure to the soil to ensure you have a healthy soil. This is a good tip for almost everything you want to grow. Feed the soil, not the plants!

Only use proper potatoes sold as seed potatoes. Whilst ones from the supermarket will grow and you can get a good crop they are not guaranteed to be free from disease.
Try blight resistant varieties.
Attend and buy potatoes at potato days organised by good local garden centres. We go to the one in Hulme, Manchester. It is a great place to buy potatoes offering a good choice and value.

Plant where there is good ventilation. Don’t squeeze them into a tiny corner hidden behind fences. Let the air flow.
Plant them early (But protect against frost) so they get more growing time before blight becomes a risk.
Try seaweed solution as a spray for health.
Earth them up. It’ll help get you a better crop too!
Remove affected foliage from plants as soon as it appears.
Compost it – the spores can only live on living tissue, so bury it deep in your heap so it rots down quickly and completely.
Sign up to blightwatch.co.uk for news about blight.
If you are badly affected then remove all the foliage. The potatoes can stay in the ground for a couple more weeks but without the tops won’t really grow much more.
Throw away rotten potatoes from your stored supply. Go through every couple of weeks. A bad smell is a sign of soft mushy potatoes.