deep, heavy | faint, quick, slight, small, tiny | puzzled, thoughtful, worried | angry, black, fierce, grim, warning | deepening

give
The boy gave a small frown.

wear
She wore a worried frown.

crease into, pucker into, wrinkle in
Her face creased into a frown.

be drawn/draw together in
His brows drew together in a frown.

deepen, grow darker/deeper
Her frown grew deeper at the memory.

crease sth
Her frown creased her forehead.

marr sth
A frown marred his handsome features.

cross sth, touch sth
A frown crossed her brow.

line

with a ~ | ~ of
a frown of concentration/disapproval/puzzlement

a frown in your eyes
He looked at her with a puzzled frown in his eyes.

a frown on your face

darkly, deeply, heavily, sharply | slightly | impatiently | thoughtfully
She studied the letter, frowning thoughtfully.

at
She turned and frowned at him.

in
He looked at the coded message, frowning in concentration.

with
He frowned with annoyance.