Dictionary / Vocabulary / 画竜点睛を欠く
がりょうてんせいをかく
to be incomplete; to feel incomplete; to lack the finishing touch
Also written 画龍点睛を欠く
最後の詰めを怠ったばかりに、画竜点睛を欠くはめになってしまったね。
You kept putting off working on the fine details on this project so it ended up lacking the finishing touches.