We asked the instructors for the culinary arts program at Fox Valley Technical College how to make great mashed potatoes. RIGHT SPUD FOR THE JOB. Stick with russet or, even better, try Yukon gold potatoes. EQUAL TREATMENT. Peel and dice potatoes into equal-sized pieces so they get done at the same time. The best part, is you don't need to make a million cuts to achieve similar size pieces, says RC Shroeder, who recommends quartering potatoes, the long way, as an easy way to achieve uniformity.