I acknowledge wht zigzag says about dirty ones, but if digging thin skinned ones at this time of year* I find that it helps to have a bucket of water close at hand - can give the spuds a quick rinse as you dig each plant, and discard any dodgy ones there and then. They also dry out quicker if they are not caked with mud.
* I found last year that 1/3 were slug ravished to the extent that they were no good for storing, and thus would have been a lot of extra work to lug home from the allotment and dry out.