A tenet of 'good' design is proper balance; ie, how each of the pieces (colours, materials, shapes, sizes, lines, textures.. so-on-and-so-forth) are arranged. Balanced design occurs when the arrangement of objects are symmetrical (the visual weight is even), or asymmetrical (the objects are unevenly placed). Harmony can exist in both these approaches.
The trick, however, arrives when arranging a grouping of objects (on the mantle, a bookcase, or perhaps an entire room), that seemingly contradict the other, with appealing balance. When mixing antique with modern, rough with refined, intricate with simple etc, it helps to find a unifying colour tone. Choose a few special pieces to standout; perhaps in size, colour or material.
Annie Woolsey, a Senior Design Associate at Roy Banse Design had this to add:
The design principle I always repeat to myself is ‘unity + variety = harmony’, this is how I guide myself when creating any sort of arrangement, large or small. In a home, I would always favour informal balance, a non-symmetrical approach. It creates a more visually interesting arrangement, and allows for a bit more freedom.
Variety is great! Mix styles & items based on how much you like them – not if you think they match. If you can unify them by texture, or colour that’s great, but don’t stress too much about this – keep it interesting, not safe.
What is really important is the visual weight of the arrangement; items that are darker in colour, or bigger carry more visual weight. If you’re putting something tall on one side of your arrangement, you can have short on the other, just make sure it’s a bit more substantial so it carries the same visual weight.
Keep in mind that there are many layout options that can be made with the items you’re using, and that they could all be considered ‘best’. I think people get overwhelmed by trying to find the most perfect solution, but in reality – there are lots of perfect solutions that will work. So, don’t rush the process.
Try lots of options. Take a step back and look at your vignette from different angles. You’ll know when you’ve got it right, because it will feel right.