My favorite eyepiece for beginners is an inexpensive 25 mm Plossl. On most scopes this provides a wide field, low power overview with easy eye-relief. An amazing amount of detail is visible through even a 4.25-inch telescope with a 25 mm Plossl. It is hard enough for the beginner to see most of such a field of view continuously. While I particularly enjoy a 55mm eyepiece on my Schmidt-Cassegrain, the eye relief is so long many beginners lose part of the field.
High power is even harder due to the very short eye relief of standard eyepieces.
Most observers have a hard time positioning their eye optimally to use a short focal length eyepiece needed for high magnification work. Alternatively, newer eyepiece designs can ease access to either high power views or wide fields. Even rough polar alignment decreases the amount of manual guiding needed to keep objects in the field of view. Simple motor drives like a tangent arm can make the transition from one observer to the next much easier. I also point out that there are a wide range of optical designs and an even wider range of costs.