The settings that I prefer to use in FaceTrackNoIR while playing Euro Truck Simulator 2.

ets2.ini

[Tracking]
Smooth=40
invertYaw=false
invertPitch=true
invertRoll=false
invertX=true
invertY=false
invertZ=false
useEWMA=true
redYaw=60
redPitch=60
redRoll=60
redX=71
redY=70
redZ=70
minSmooth=10
powCurve=18
maxSmooth=48

[GameProtocol]
Selection=4

[KB_Shortcuts]
Keycode_Center=46
Shift_Center=true
Ctrl_Center=true
Alt_Center=false
Keycode_StartStop=30
Shift_StartStop=true
Ctrl_StartStop=true
Alt_StartStop=false
Keycode_GameZero=45
Shift_GameZero=true
Ctrl_GameZero=true
Alt_GameZero=false
SetZero=true
SetEngineStop=true
Keycode_Inhibit=0
Shift_Inhibit=false
Ctrl_Inhibit=false
Alt_Inhibit=false
Inhibit_Pitch=false
Inhibit_Yaw=false
Inhibit_Roll=false
Inhibit_X=false
Inhibit_Y=false
Inhibit_Z=false
Enable_ReverseAxis=false
RA_Yaw=40
RA_ZPos=-20
RA_ToZPos=50

[Curves]
Yaw_point1=@Variant(\0\0\0\x1a\0\0\0\0\0\0\0\0@.\0\0\0\0\0\0)
Yaw_point2=@Variant(\0\0\0\x1a@F@\0\0\0\0\0@@\x80\0\0\0\0\0)
Yaw_point3=@Variant(\0\0\0\x1a@a\xc0\0\0\0\0\0@?\x80\0\0\0\0\0)
Yaw_point4=@Variant(\0\0\0\x1a@f\x80\0\0\0\0\0@I\0\0\0\0\0\0)
Pitch_point1=@Variant(\0\0\0\x1a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0)
Pitch_point2=@Variant(\0\0\0\x1a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0)
Pitch_point3=@Variant(\0\0\0\x1a@O\x80\0\0\0\0\0@D\0\0\0\0\0\0)
Pitch_point4=@Variant(\0\0\0\x1a@d\xc0\0\0\0\0\0@I\0\0\0\0\0\0)
Roll_point1=@Variant(\0\0\0\x1a\0\0\0\0\0\0\0\0@I\0\0\0\0\0\0)
Roll_point2=@Variant(\0\0\0\x1a@X\xc0\0\0\0\0\0@I\0\0\0\0\0\0)
Roll_point3=@Variant(\0\0\0\x1a@Z\0\0\0\0\0\0@I\0\0\0\0\0\0)
Roll_point4=@Variant(\0\0\0\x1a@f\x80\0\0\0\0\0@I\0\0\0\0\0\0)
X_point1=@Variant(\0\0\0\x1a@\x14\0\0\0\0\0\0@\x14\0\0\0\0\0\0)
X_point2=@Variant(\0\0\0\x1a@\0\0\0\0\0\0\0@\x14\0\0\0\0\0\0)
X_point4=@Variant(\0\0\0\x1a@R\xc0\0\0\0\0\0@I\0\0\0\0\0\0)
Y_point1=@Variant(\0\0\0\x1a\0\0\0\0\0\0\0\0@$\0\0\0\0\0\0)
Y_point2=@Variant(\0\0\0\x1a@2\0\0\0\0\0\0@$\0\0\0\0\0\0)
Y_point3=@Variant(\0\0\0\x1a@B\x80\0\0\0\0\0@<\0\0\0\0\0\0)
Y_point4=@Variant(\0\0\0\x1a@R\x80\0\0\0\0\0@I\0\0\0\0\0\0)
Z_point1=@Variant(\0\0\0\x1a@\b\0\0\0\0\0\0@\x18\0\0\0\0\0\0)
Z_point2=@Variant(\0\0\0\x1a@D\x80\0\0\0\0\0@B\0\0\0\0\0\0)
Z_point3=@Variant(\0\0\0\x1a@S\x80\0\0\0\0\0@G\0\0\0\0\0\0)
Z_point4=@Variant(\0\0\0\x1a@Z@\0\0\0\0\0@I\0\0\0\0\0\0)
X_point3=@Variant(\0\0\0\x1a@@\xa6\x66j\0\0\0@@\xa6\x66j\0\0\0)

[PPJoy]
Selection=1

[FSUIPC]
LocationOfDLL=C:/Program Files/Microsoft Games/Flight Simulator 9/Modules/FSUIPC.dll

[TrackerSource]
Selection=0

[FTIR]
useTIRViews=false
useDummyExe=true

[SMTracker]
FilterLevel=1