/etc/X11/xorg.conf.d/

20-intel.conf

Section "Device"
        Identifier "Device0"
        Driver "intel"

        Option      "AccelMethod" "SNA"
# prevent KDE Plasma CPU usage, https://wiki.gentoo.org/wiki/Intel#KDE.27s_plasma_eating_CPU
        Option      "TearFree"    "true"
EndSection

20-synaptics.conf

Section "InputClass"
	Identifier "synaptics touchpad catchall"
	MatchIsTouchpad "on"
	MatchDevicePath "/dev/input/event*"

	Driver "synaptics"

	Option "SHMConfig"		"True"
	Option "RTCornerButton"		"0" # 2 is default
	Option "RBCornerButton" 	"0" # 3 is default
	Option "HorizTwoFingerScroll"	"1"
	Option "VertTwoFingerScroll"	"1"
	Option "HorizEdgeScroll"	"1"
	Option "VertEdgeScroll"		"1"
	Option "TapButton1"		"1"
	Option "TapButton2"		"2"
	Option "TapButton3"		"3"
	Option "CoastingSpeed"		"20" # 0 (disabled) is default
EndSection

30-logitech-receiver.conf

Section "InputClass"
	Identifier "Logitech receiver"
	MatchIsPointer "on"
	MatchDevicePath "/dev/input/event*"
	MatchProduct "Logitech USB Receiver"

	Option "AccelerationProfile"  "3"  # smooth linear (soft knee, then linear)
	Option "ConstantDeceleration" "2"  # halve mouse dpi without sacrificing accuracy
EndSection

30-logitech-usb-laser-mouse.conf

Section "InputClass"
	Identifier "Logitech USB Laser Mouse"
	MatchIsPointer "on"
	MatchDevicePath "/dev/input/event*"
	MatchProduct "Logitech USB Laser Mouse"

	Option "AccelerationProfile"  "3"  # smooth linear (soft knee, then linear)
	Option "ConstantDeceleration" "2"  # halve mouse dpi without sacrificing accuracy
EndSection

80-any-pointer-mouse.conf

Section "InputClass"
	Identifier "Any Pointer Mouse"
	MatchIsPointer "on"
	MatchDevicePath "/dev/input/event*"

	Option "Emulate3Buttons" "False"

	Option "EmulateWheel" "True"  # for faster scrolling
	Option "EmulateWheelButton" "2"  # middle mouse button
	Option "XAxisMapping" "6 7"  # left right
	Option "YAxisMapping" "4 5"  # up down
EndSection

80-wacom-tablet-pen-scrolling.conf

Section "InputClass"
	Identifier "Bamboo Tablet"
	MatchDevicePath "/dev/input/event*"
	MatchProduct "Wacom"

	Option "Button2" "4"
	Option "Button3" "5"
EndSection