I apologise if this has been covered already. I want to store one of my guitars away for the foreseeable future. Is it best to stand it up in its case and back off string tension slightly?
Standing upright (in a case...) is the preferred method from what I've read/heard.
Also a good idea to open & air out the case once / twice a year if possible to reduce moisture build up.
I've even put a sheet of wax paper between the strings & fretboard to eliminate the chance of oxidizing and/or denting the frets...