Last November, I cut a twig from a willow tree near my house, put it into water and waited for the roots to grow. They did after a while and so I planted it and from time to time cut it to make it into a nice bonsai. I wouldn’t call it a proper bonsai tree yet, but I like how it has turned out so far.
I think willow trees are a good way to start into bonsai. They grow quickly and they are easy to maintain. (My five year old avocado tree died, by the way and my bought olive tree might be dead, too.)
This is the only tree I haven’t grown from seeds.
Here’s a video of it with a 360° view: