Below are some useful recipes. See also:

• Using AutoHotKey to map keys on the Amtelco KB163 Unified Keyboard.
• Using AutoHotkey to make a second mouse into a multimedia control

; General controls:
;   Win+Esc       to reload
;   Win+Shift+Esc to exit
;   Win+Ctrl+Esc  to exit
#Escape::Reload
#+Escape::ExitApp
#^Escape::Edit

; Win+Backtick = Sleep
#`::DllCall("PowrProf\SetSuspendState", "int", 0, "int", 0, "int", 0)

; Win+M = toggle mute
#m::Send {Volume_Mute}

If you have a second monitor above the main one, this script will help you still be able to click stuff at the top of the screen without accidentally wandering into the upper monitor.

SetupClipCheck() ; enable the mouse confinement system (defined below)

; get access to the winapi ClipCursor function, which limits cursor boundaries
ClipCursor( Confine=True, x1=0 , y1=0, x2=1, y2=1 ) 
{
 VarSetCapacity(R,16,0),  NumPut(x1,&R+0),NumPut(y1,&R+4),NumPut(x2,&R+8),NumPut(y2,&R+12)
 Return Confine ? DllCall( "ClipCursor", UInt,&R ) : DllCall( "ClipCursor" )
}

; count the number of loop iterations the mouse has been near the top and un-confine the mouse if there's been enough
SetupClipCheck() {
 SetTimer, ClipCheck, 10
 return
}

top_tick_count := 0   
ClipCheck:
 CoordMode, Mouse, Screen
 MouseGetPos,x,y
 ;ToolTip,%x%:%y%:%top_tick_count%

 If (y < 10) {
   top_tick_count++
 } Else {
   top_tick_count := 0
 }

 if (top_tick_count>15) {
   ClipCursor(False)
 } Else {
   ClipCursor(True, -10000, 0, 10000, 10000)
 }
 return

XButton2::Media_Play_Pause
XButton1::Media_Next

Press F7 to toggle auto-clicking over and over as fast as possible.

i:=0 
F7::SetTimer, Spam, % (i:=!i) ? "10" : "Off" ; uses ternary

Spam: 
   Click
   Send {LButton}
return

Windows by default binds Win+X, Win+B, and Win+Space to stuff I don't care about. The script below will remap these to Win+Ctrl+<key>, which you can bind to apps without issue.

; WinAmp+Launchy remaps
#x::#^x
#b::#^b
#space::^#Space

; Auto mouse click: 
;  Win+Shift+I      to auto click slowly
;  Win+Shift+Ctrl+I to auto click quickly
;  Win+I            to auto stop
#+i::
SetTimer DoClick,500
SoundBeep 440,100
SoundBeep 660,100
return
#+^i::
SetTimer DoClick,50
SoundBeep 440,100
SoundBeep 660,100
SoundBeep 880,100
return
#i::
SetTimer DoClick,off
SoundBeep 660,100
SoundBeep 440,100
return
DoClick:
  Send {LButton}
  SoundBeep 200,10
return

The F5 for reload only works if the active file is the most recently opened.

; FoxIt keys: F5=reload
#IfWinActive, ahk_class classFoxitReader
F5::Send ^w!fr1
#IfWinActive

; Terraria: middle click is turbo left click
#IfWinActive, ahk_class WindowsForms10.Window.8.app.0.ea7f4a_r16_ad1
MButton::
	SetTimer DoClick,50
	SoundBeep 880,50
	return
MButton up::
	SetTimer DoClick,off
	SoundBeep 440,50
	return
#IfWinActive

The code below will replace the annoying help popup with a low-pitched beep. Change "SoundBeep…" to "Return" for silent operation.

; Suppress F1 in Explorer/Word/Excel -- replace the annoying help popup with a low-pitched beep
#IfWinActive ahk_class CabinetWClass
F1::SoundBeep 110,100
#IfWinActive ahk_class OpusApp
F1::SoundBeep 110,100
#IfWinActive ahk_class XLMAIN
F1::SoundBeep 110,100
#IfWinActive

; Ctrl+W = hold W (auto-run)
; Ctrl+LButton = hold LButton (auto-mine)
; Ctrl+RButton = hold RButton (auto-use)
; MButton = Sprint without double-tapping W
; Ctrl+MButton = hold MButton (auto-sprint)

#IfWinActive Minecraft ahk_class SunAwtFrame
^w::
 Send {w down}
 SoundBeep 500,100
 return

^LButton::
 Send {LButton down}
 SoundBeep 500,100
 return

^RButton::
 Send {RButton down}
 SoundBeep 500,100
 return

MButton:: 
 SetKeyDelay 55
 Send {w down}{w up}{w down}
 KeyWait MButton
 Send {w up}
 return

^MButton:: 
 SetKeyDelay 55
 Send {w down}{w up}{w down}
 SoundBeep 500,100
 return
#IfWinActive