If you’re playing the guitar frequently, you can keep it assembled. If you’re not playing it frequently, we recommend keeping it stored in the original case.
If your climate is dry and you have a collapsible wood model, you can use a humidifier and store the guitar in the original case, and then seal the case in the plastic bag that came with the original guitar (or large trash bag). Be sure to check the guitars’ humidity in a month to be sure it’s not over-humidified. If you have a carbon guitar, it should be worry free.
If you keep the guitar assembled, be aware that if you have swings in humidity the wood may swell from the increase in moisture and thus require more force to unscrew the main bolt. To make it easier to unscrew, you can press against the neck while grabbing it near the headstock for leverage, and untwist the bolt with the other hand.