Choose the closest substitute based on whether you need coconut flavor (coconut sugar syrup) or just sweetness (agave, honey, maple).
Swap using the listed ratio; for agave, start slightly lower (¾:1) because it can taste sweeter per spoon.
If the substitute is thinner than coconut nectar, simmer 3-5 minutes (or reduce in the pan) to thicken for drizzling.
If it tastes too strong, dilute with 1 teaspoon warm water at a time, then taste again.
For baked goods and glazes, give it 1-2 minutes to set and re-check sweetness after it heats.