I found an image where someone aged a man to show you how a smoker would look in 20 years time
My 2nd link below shows a group of smokers in tehir 20's and I think they all look a bit worse for wear, especially the 22 year old woman, she looks alot older. Smoking ages your skin, you get fine lines and wrinkles around your mouth. I've seen so many smokers with grubby yellow hands. You may also get stained teeth aswell as fingers. It accelerates the aging of your skin, It alters conditions in your mouth causing bad breath and can lead to early hair loss, so all in all it's not good!
I just took another look at those smokers on my second link and they definitely do look unhealthy, a bit pasty and have bags under the eyes.