Resetting Mac SMC and NVRAM / PRAM

Having just applied Apple's latest update to El Capitan and temporarily lost my bluetooth connection, I thought I'd post this as a reminder to myself if nothing else . .

(My bluetooth was fixed by resetting the SMC)

***EDIT***
Remove any devices e.g. USB/Thunderbolt and try a reboot first: I tried recently to reset as my bluetooth had died again. Resetting with two displays plugged into the thunderbolt ports didn't work

See also here https://support.apple.com/en-us/HT203646

Also, for bluetooth, try deleting the bluetooth plist in /Library/Preferences
***EDIT***

Resetting the NVRAM / PRAM

• Shut down the Mac completely (not just standby)
• Power on the Mac
• Immediately after the startup 'boing', press and hold Command, Option, P and R until the Mac restarts and you hear the second 'Boing' (yep, this is a finger stretcher!)
• Apple's link here  https://support.apple.com/en-gb/HT204063

Resetting the SMC

(Note that this is for Macs with non-removable battery - check Apple's notes first)

• Shut down the Mac completely (not just standby)
• Make sure you have a power supply plugged in
• Press Shift, Control, Option (on the left side of the keyboard) and the Power key all at the same time
• Release them all at the same time
• Apple's link here https://support.apple.com/en-gb/HT201295

(BTW 'Option' is the key that is marked with  'alt' on the top and a symbol on the bottom, at least on UK keyboards - see also https://en.wikipedia.org/wiki/Option_key)