How to Take a picture at Night

FROM TRIPOD
-Use a tripod
-Turn off image stabilization (IS)
-Use a self timer or a shutter release cable or wireless remote
-turn on the mirror lockup mode

FROM HAND
-Increase ISO
-Hold the camera steady
-turn on the mirror lockup mode
-image stabilization feature ON

SPECIAL
period of around 20 minutes after sunset but before it gets completely dark, when the sky has a rich blue color, and is not a complete, flat black.

SOURCE