This is my simple keyboard and mouse set up changed from defaults setting since the first day i played this game. This setup was designed around having your fingers in the most relaxed and natural position possible. Works for large and small hands and is for general comfort over long sessions of play. I use this setup in almost every single fps game.

These are my rebinds:

Crouch - Default = Left Ctrl > Rebind to Shift

Sprint - Default = Shift > Rebind to Caps Lock

Jump - Default = Space Bar > Rebind to Right Mouse Button

Weapon Secondairy Mode - Default = Right Mouse Button > Rebind to Middle Mouse button.

Medic = X

This set up removes the use of the space bar, freeing up your thumb for medic. Your left hand will be in a more compact position and you will no longer strain to use left CTRL with your pinky.