Olive oil does work great for improving the complexion on your face but you should mix the olive oil with some lemon juice first.
After mixing the Olive Oil with some Lemon Juice you can apply it to your face and leave it on overnight or for a few hours per day.
I leave the olive oil and lemon juice on my face overnight for best results.
You can also use Vinegar on your face for improving complexion and removing dark spots and also to unclog your pores.