Tom, help yourself to some fish.

汤姆，随便吃点鱼。

Help yourself to a clean towel.

请随便拿一条干净毛巾用。

Help yourself to what you need.

有需要尽管取用。

Help yourself to this apple pie.

请随意吃点苹果馅饼。

Help yourself to some more duck!

请再吃点鸭肉吧！