I bought a lot as it's very popular and easy to use, it stays on your lip all day. It doesn't affect your colour when you drink and eat. 

Press a small amount onto your lip, apply it around your lip, make sure it covers all your lip. (Please be aware it is very sticky). After 1 minute or so, you can feel it becomes dry, then peel off the top layer, DONE! 

Due to my lip condition is very dry, so I like to apply a lip balm before I apply any lip cosmetics. So I would like to recommend you to do that as well just for the better result.