The "Why don't" pattern is a very polite, very smooth way to suggest something.

Why don't”句型是一种非常礼貌、流畅地提出建议的方式。

Why don't 课堂 - SpeakingMax英语口语达人

So when District Attorney Eddie Jordan appeared before the city council, it wasn't smooth sailing.

NPR: Criticism Rises for New Orleans DA

The transition from market stall to public company wasn't smooth.

CNN: How L'Occitane went big in Japan

I'm not sure if it's just my phone, but when closed, the cover sticks up about 1 or 2mm and isn't smooth when running your fingers up and down.

ENGADGET: Hands-on with Motorola's RAZR V3 for Cingular