If I plan to use mine the very next day, I'll usually leave it strung. However, anything longer then that I unstring it. Always use a bow stringer. I have two different one'e. One has leather that slips on the very tips, and one has rubber that fits on the back of the limb. the leather one was much more expensive, however, I feel the ruber one is safer to use.

Like others have said, never leave it standing upright in the corner, strung or unstrung.