The following details will help you become more aware of what to look for in a quality, adjustable instrument. And also the one that is inspected and properly adjusted.
1. Pick your Size- Guitars are not a one-size-fits-all! Picking the correct size is most important because if you are uncomfortable playing something too large for you, then you will have less motivation to pick it up to play.
2. Unpack and visually inspect guitar for shipping damage.
3. Check neck joint for the cracks and defects.
4. Check inside of guitar with an inspection light and mirror as necessary.
5. Tune guitar to standard pitch. The tuning machines should operate smoothly and accurately with the strings wound properly around the tuning post. Check to tune machine screws for proper tightness.
6. Check whether the strings are properly wound around tuning post to maximise tone and ensure less wear on tuning machines.
7. Inspect neck angle with a straight edge.
8. Bridge and Fingerboard should be about the same height above the guitar top. A bridge that is too high or too low can indicate a poor neck angle.
9. For acoustic guitars, the wood bridge should be securely glued with no open gaps.
10. String height or action at the nut should be low at the first fret, which results in all six strings being easy to play. Conduct preliminary inspection of action and overall playability.