Mix materials for texture. If you’re ever decorating and you’re following that symmetry rule but your vignette is still looking “flat” to you, try swapping out a couple of items to vary the materials. I always try to use at least one item of each material that is wood, glass, metal, and greenery. Add in paper and natural weave fabrics too, if you can make it work. The more variety of materials you have, the more texture you’ll create.
