When it comes to skin lightening, using lemon will prove to be most effective on your skin. Lemon will help reduce the dark spots and blemishes on your skin. All you need to do is cut a lemon into two and rub one half onto your skin. Leave it for 10 minutes and then wash off with cool water. But remember not to step out in the sun immediately after using lemon on your skin. Lemon is the best natural remedy for skin lightening. It helps to reduce the blemishes and dark spots.