Throw in the Towel

When I finally decided to give up religion, I threw in the cowl.

When I finally decided to give up frowning, I threw in the scowl.

When I finally decided to give up spelling, I threw in the vowel.

When I finally decided to give up poetry, I threw in the Howl.

When I finally decided to give up carpentry, I threw in the dowel.

When I finally decided to give up gardening, I threw in the trowel.