never miss a trick

not/never miss a trick (never fail to make use of an advantageous situation for one's benefit ) — никогда не упускать возможность / шанс; всегда использовать преимущество; все замечать, ничего не упускать

Example 1: You can rely on Sarah to get what she wants, she never misses a trick (=tries every deception and device there is to get what he wants.) — своего не упустит

Example 2: When it comes to the commodities market, Mark never misses a trick.

Example 3: Dad may seem absentminded, but he doesn't miss much.

сf.:
[себе на уме]
[know which side one's bread is buttered on]