Most of the time your skin appear dull because of layer of dead skin, just remove it and you can see instant glow on your face. For this you will just need a lemon and some salt. On a lemon slice put some sale and use this to scrub your face gently.
Do scrubbing for few minutes and wash it off with normal water
After this apply a face pack for 15 minutes. For this in rice flour mix honey and lemon juice, if required you can also add some water. Apply it all over your face and wash it off after 15 minutes
Pat dry your face and apply moisturizer.
Look this video:
https://www.youtube.com/watch?v=iqYwrhQaZJw