Add storage space by creating a closet area that maximizes the room under the stairs if there is room. Remove old fixtures and replace them with a closet system that includes shoe storage, a short rod for rarely worn coats and large shelves for suitcases. Build in a series of shelves to hold covered plastic bins for holiday decorations or collections of family photos. Use a top shelf for oversized pots that are only used once or twice a year. Paint the closet interior a light color to brighten the space.
Build a series of wooden boxes that, when set atop each other, mimic the rise of the staircase steps if the space under the stairs is enclosed. Set the boxes flush to the wall of the staircase that faces the room, and secure them in place by screwing them into the studs in the wall. The tops of the boxes create a decorative staircase paralleling the real staircase, and the interiors provide storage space for books, wine bottles or curios. Paint or stain the boxes to match the basement decor.
Open up the basement by removing the wall under the stairs that faces the rest of the basement if there is such a wall. if you don't need an enclosed closet under the stairs, use the space as a mini-office by installing a small desk and placing a two-drawer file cabinet under the lower steps. Add shelves above the desk or mount a flat-panel computer monitor to the wall. Paint the area white to add light, install a pole lamp with directional bulbs and hang curtains to close off the area when you're entertaining in a basement family room. Finish the underside of the stairs with Sheetrock if the treads are exposed.
Freshen up the stairs by replacing the treads and risers with prefinished wood and update the handrail and balusters. If the basement is primarily used as a casual area, paint the stair treads alternating bright colors. Turn them into an educational tool for little kids by painting numbers on them in order, encouraging the kids to count as they climb the stairs. Paint the stair stringer and handrail to match the new treads and risers.