Let them bark. When they walk near to u with suspicion, stay still. Let them sniff u. Speak to them in low cooing gentle voices. Let them lick ya hand. And slowly squat down to their level. Never, ever bark (literally) back at them. I know a friend who does that, the dog chases her and she starts running. Sometimes I wish I can give her a slap.
And never, ever bend over a dog (a strange dog or a familiar one) and start patting it on the head or screech in a high-pitched voice. Dogs have exceptionally sensitive ears.
If u're still in doubt, get some dog biscuits and give them some. Feed them by hand and start rubbing them on the head and scratching them.
Never fear them. Somehow, animals can smell ur fear and will try to walk up to u even nearer simply because they know u're frightened of them. Let them sniff. Its just a sniff, u wun lose a chunk of meat that way.