I don't base many of my child training and growing decisions on what I was doing at their age...cuz...nuff said there.
I DO however base decisions upon the agregate of my knowledge of this society and child development. I've been studying it since I was a small child. I've had to emulate real-life.
Fortunately, my ex and I are greatly on the same page:
Son: Had an ever increasing length of liberty from the time he could walk. As he gained abilities and demonstrated responsibilities, he got to do things like ride his bike ALL around the neighborhood (age 7). Peers...no such liberties.
At 12, we began to cut the rope entirely in some venues. This includes the vast majority of his life. As my ex says;"we are trying to raise a man, not a perpetual boy. If we raise a dependent, perpetual boy, his life will be greatly less."
Heck....ice skating on his own at 12? Yes! He currently skateboards and long-boards ALL around town as long as he has his street-gang in tow. He knows enough to not be alone or at-risk 'out there.' I've also taught him some fantastically devastating defense tachtics that would discourage any creep.
Daughter: Age 11. No where near as responsible as Son. She is in her own head 90% of the time. Thus, not paying attention to her surroundings. Not interested in being alone ever. She does not wander out there and will not allow us to 'drop her off' anywhere. She is not capable yet...period. This year however, she wants to surf as her 'own thing.' So she will be allowed.
For me, its all about ability and track-record of prior responsibility.