Find or purchase an oblong basket and place it on the back of the toilet tank. Line up three rolls in the basket or create a six-roll pyramid. The toilet paper will be out in plain sight but still look tidy.
If you have an enclosed sink with a cabinet underneath, store the extra rolls of bathroom tissue hidden away but within reach. Make a neat line of rolls on the side of the cabinet nearest to the toilet, so you can reach them in a sitting-down emergency.
Hang a decorative tote bag below your toilet paper roll holder. Fill the bag with two or four spare rolls, depending on the size of the bag. The paper will be handy but out of sight, and you can use the bag itself as a design element by choosing one with a decorative face.
Find a tall vase that's at least 6 inches across at the opening. Most ordinary rolls are about 5 inches across, so they will fit with room to spare. Drop the rolls in the vase in a stacked configuration and place it in a corner.
Hide your extra roll with a totally kitsch and retro toilet paper cover doll. These plastic dolls were a favorite of grandmothers all over the country in the 1970s. They consist of an often frightening plastic doll head and body attached to a brightly-colored crocheted dress with a large flared skirt. Place the doll over the roll and the paper acts as a hoop beneath the skirt, making it flare out into the ultimate in 1970s grandmother chic.