Place objects exactly on planar surfaces of other objects.
Create the object you want to place, move the pivot with activated transform tool at exact bottom of your object. now choose the insert tool and choose clone. clone will take active object. if you drag now onto another object, the clone will be placed exactly on it’s surface according to normals direction (normals are perpendicular on every polygon face to define visible and invisible side)
Well, theoretically a bit confusing…I’ll try to make a vid.
Tap, hold & drag to rotate object before release