tight
thick
thick coils of blonde hair

in a coil
She wore her hair in a neat coil.

coil of
a coil of rope

tightly
loosely
up
He coiled the rope up tightly and put it away.

around, round (esp. BrE)
The snake coiled itself around a branch.

into
Her hair was neatly coiled into a bun.

Coil is used with these nouns as the object:
rope