I usually start with the G string pair (thickest), and continue with the other pairs (D, A, E) till the mandolin is fully tuned:
- Identify the G strings and G tuning pegs using the image below.
- Pick one of the G strings of the pair, and see if the online mandolin tuner shows your are in-tuned.
- Tighten or loosen the corresponding G tuning peg, till you have a match.
- Repeat for both strings of each pair (G, D, A, E)
Note: If you turn one tuning peg of the pair and the sound does not change, stop turning to avoid breaking the string. You are possibly turning the wrong peg. Please try the other peg of the pair!