Cigarettes- My brother is 6 years older than me, and started smoking around 16... so I was 10. I was never an habitual smoker, between the ages of 10 and 15 I smoked a pack a year, and always in secret. I stopped when my mom found out, at 15. Since then, I will smoke cigarettes when I am drinking heavily, so extremely rarely. I do enjoy the hookah every few weeks, though.
Weed- I held off til I was 31! All of my high school friends were stoners, too. They would offer, I would refuse, and they would say "Cool, more for me." and just let it be. I'm glad I have since done so, but I'm also glad I waited on that one.