This is my latest creation - a miniature and dwarf conifer rock garden with a water feature for water plants. Conifers - mostly evergreens, pines, spruce, etc, but include decidious trees also such as the Taxodium aka Bald Cyprus and the Ginko - a very ancient tree. There is both a miniature Taxodium and a miniature Ginko in the mix. They will both get to be about 3' tall in ten years. I'm still waiting for the native water plants to come up.
Conifers are very useful for four season garden interest and can be the backbone of the garden. They almost always retain thier needles (leaves) with a few decidious exceptions, noted above. There is a very wide diversity of forms and colors. My favorite conifer author - Richard Bitner, has a number of conifer books out that are very useful for reference.