Not sure if this is art, craft, or gardening. Pebble mosaic "carpet" is beautiful. For this pebble-mosaic patio, the author modified a classic Persian carpet design to represent the creation of the universe.
Love the idea of growing herbs/plants between stepping stones as the ground landscaping. If you have to retain a tree growing out of the middle of your patio - make a feature of it as they've done here by edging it with box topiary.