If the instrument will not be played for a while, how it is stored has a direct effect on the condition you find it in later. Loosen the strings gradually to take the load off the body; they do not need to come off entirely, because a little remaining tension helps the instrument hold its shape.
How far to loosen. The strings should still sit flat on the front nut and on the bridges, without sagging or wobbling sideways. Bass strings are thicker and carry more tension to begin with, so matching the feel of the treble end is enough; there is no fixed number of turns. Work from the bass end upward so the soundboard unloads gradually, and never take one string all the way slack at once.
Storing the bridges. Take them off and bag them by register, resting on their feet rather than stacked. A foot that deforms will no longer sit flush on the soundboard, and the tone will turn hollow. A soft cloth or a sheet of paper underneath keeps them off hard surfaces. Mark the positions on the soundboard before you remove them — a strip of tape or a photo saves a long search when you set the instrument up again.
Where and how to place it. Keep it out of direct sun and away from radiators and air-conditioner outlets, and do not stand it against an outer wall or directly on the floor, where temperature and humidity swing most. For long storage, lay the instrument flat on a firm surface rather than leaning it against a wall: leaning puts the weight of the body on one rim for months and loads the frame unevenly. A board or a moisture mat underneath keeps ground damp away.
What to cover it with. A dust cover or a clean soft cloth is enough, and the fabric should breathe. Do not seal the instrument inside plastic — trapped moisture does more harm than leaving it open. In a humid season a small desiccant pack can go in the case, but keep it off the finish.
The order to bring it back. Check the body before restringing: look for cracks in the soundboard, glue lines opening at the rims, and loose fittings. If all is well, refit the bridges and bring the strings up in two or three passes, hours apart, then tune and watch the pitch for a day or two. Sharp swings in humidity are the main thing to avoid in storage, so let the instrument settle in its new room for half a day before tuning it.