For the basement stairs: cabinets, stairs with flip up steps and very narrow stairs. Each step goes up one at a time for each foot. It is sort of spaced so you are putting one foot per step with a steeper step. Very space-saving.
An essential part of a kitchen is storage. Buyers want a kitchen that has a lot of space and storage and also that is clutter free. This picture gives a house flipper an example of how they can create storage areas when reconstructing the kitchen.