I find potato is best cooked in the steaming basket then mashed in the bowl with the butterfly at speed 3 for about 10 sec to start with girls. I add butter and S & P then a small amount of milk after the 10 seconds and mix again for a few more seconds. I find some types of potatoes need no milk but none of them need a whole lot. Glue potatoes are usually beaten too long. Everyone has their favourite method though so it's up to you to work out what suits you best.