Jhin & Sona Synergy
Jhin ADC and Sona Support win 50.6% of 3,107 Low Elo games together, -0.7 points vs expected, 2-patch window 26.19-26.20.
Researched on LoL patch 26.20. Tips are written to hold at any rank; stats come from Low Elo ranked games up to patch 26.20.
Playing the duo
Hymn of Valor(Q) can tag an enemy for Deadly Flourish(W): Jhin's W roots targets recently hit by an ally, giving the pair a ranged follow-up to Sona's poke.
How to play as Jhin
Trade around Sona's poke or the slow from Song of Celerity(E)-empowered Power Chord(P), then disengage after your 4th shot instead of staying for a long fight during your reload.
How to play as Sona
Look for short poke trades: Hymn of Valor(Q) or Power Chord(P) can let Jhin land Deadly Flourish(W), while Aria of Perseverance(W) helps blunt the return damage.
Sources
These notes come from r/sonamains, checked against the champions' abilities.