Pre-5.0 Android
- Shut down phone
- Hold Power and Volume Down(-) buttons for about 10 seconds
- Select Recovery
- When you see the dead android with a triangle and exclamation mark Press and hold Power and Volume Up(+) buttons for two seconds then release (holding too long with reboot the device)
- You will now see the recovery menu
Android 5.0 and above (Lollipop and above)
- Shut down phone
- Hold Power and Volume Down(-) buttons for about 10 seconds
- Select Recovery
- When you see the dead android with a triangle and exclamation mark Press and hold the Power for two seconds and while still holding the power button, click the Volume Up(+) button.
- You will now see the recovery menu.
Sources:
http://forum.xda-developers.com/moto-g/general/lollipop-stock-recovery-how-to-enter-t2964477