A drop of essential oil is not a drop of carrier. On skin, that difference is the whole craft.
Start with a 2% dilution for adult body work: about twelve drops of essential oil in 30 ml of a carrier such as jojoba or fractionated coconut. Face work sits closer to 1%. Children, pregnancy, and broken skin are a different conversation — skip them unless you already know the oil.
Phototoxic citrus (bergamot, lemon, lime, grapefruit expressed from peel) stays off uncovered skin before sun. Steam-distilled citrus is usually kinder. If the bottle does not say which, treat it as phototoxic.
Warm the carrier in the palm first, then add the drops. You will smell the oil more honestly that way, and you will not chase a cold, stubborn blend around the bottle.
The bottle on the bench is the one you will actually use. Dilute it, cap it, write the date.