itchy trigger finger

fat finger

A supposed cause of typographical errors, especially keyboard errors, caused from erroneous key presses or typing errors on touchscreen devices.

finger in the pie

A share in the doing of something; involvement.

finger to the wind

An attention to or focus on or awareness of current or prevailing trends, public opinion, or shifting circumstances.

fucked by the fickle finger of fate

Victimized by bad luck.

get one's finger out

To proceed with the matter in hand.

have one's finger on the trigger

To be prepared to kill someone else or as with a firearm.

itchy feet

A strong desire to travel; wanderlust.

lay a finger on

To merely touch.