My understanding of these items is that the strings are tuned chromatically. If this is the case then once you identify the lowest string it's a simple matter with a tuner to tune the rest, a semitone a time for each string.

It's possible that some notes in the chromatic scale are omitted. A way of checking the notes that are necessary is to write down the notes on the chord bars on a music staff to see if any are never used, eg if there were three chords C G and F then the required notes would be C E G for the C chord F A C for the F chord and G B and D for the G chord. so for those three chords you would need no sharps or flats.

Stu