Flowering dogwood works very well as bonsai and there is a number of dogwood species. You could go by cutting or seedling but nursery stock with a good low branch selection is best. Keep in mind, with seedlings and cuttings you will have to wait many years to not only get something that starts to look like a bonsai but to flower as well. Some species of Wisteria, crabapple and cherry can take around ten years (depending on the species) before they begin to flower.

If I bought a pink dogwood from lowes can I reduce the leaf size? I know I can't reduce the flower size.