Sake is one of the most food-friendly drinks there is. Its gentle acidity and umami sit comfortably beside dishes that can fight with wine.
You do not need rules so much as a few dependable starting points.
A few pairings to trust
Crisp ginjo with sashimi and oysters. Fuller junmai with grilled fish, roast chicken or dumplings. Warm honjozo with hot pot and simmered dishes on a cold evening.
Beyond Japanese food, try aromatic daiginjo with soft cheeses, or a sparkling sake as an aperitif in place of Champagne.
The one guideline
Match intensity to intensity — delicate with delicate, rich with rich — and let everything else be an experiment worth making.