Topiary trees are plants (usually evergreen shrubs like boxwood or yew) that are trimmed into decorative shapes like balls, cones, spirals, or even animals. They’re shaped by regularly pruning new growth using shears, often following a frame or guide when doing complex designs, simple ones like spheres are just done by eye with practice. I’ve tried a small spiral once, and honestly, the key is patience and frequent light trimming rather than cutting too much at once.