If you're walking down the sidewalk in a party of three or four, and someone is walking toward you, break into single file so the person walking toward you can pass. Honestly. Don't make the person walking toward you step off the sidewalk or onto a lawn to go around you. I am pretty sure I learned this when I was about 5 years old.
If you're driving, and you want to turn left on a green light or right on a red, but someone is crossing the street, let them safely arrive at their destination - the other side of the street. Don't just turn anyway! Especially if that person is walking two cute dogs.
If you're walking, and someone has two cute little white dogs, and you want to pet them, ask first before sticking your hand in the poor puppy's face.
I passed a woman on the street the other day who was smiling and saying "Hello," to everyone she passed. I watched a man riding a bike in Toronto last week who was snarling "Whatever," to everyone he whizzed past. It reminded me of the Leonard Cohen song : I saw a beggar leaning on a wooden crutch, he said to me "You must not ask for so much....I saw a women leaning in her door, she said to me, "Hey, why not ask for more?" Who would you rather be?
Who are you as walk from school, to work, or home? Be kind to strangers; give others the right of way; offer to hold a door. A few good deeds and pleasantries throughout the day can go a long way.
And that's my advice on "Streetiquette."