When you think of yo-yoing you think of Walking the Dog, one of the most iconic tricks other than Rock the Baby. When walking the Dog, you've to have a good sleeper so that the yo-yo will stay spinning, and come back to your hand after you do the trick. Make sure you have a good spinning yo-yo. Put it on the ground, and you can walk along with the yo-yo like you're walking a dog.
There's also a different variation of Walking the Dog, a trick called The Creeper. Like Walking the Dog, you walk the dog out, but then it returns to your hand in a different manner. You walk the dog out, and the dog walks right back to your hand, on the ground. That's called The Creeper.
It's really, really important that you have a good, strong throw, and the yo-yo spinning good. It the yo-yo slows down too much, the yo-yo won't come to your hand. It will die out like so, and you killed the dog.