How about some of those tough wire hoops - as for tomatoes, gladiolus, or delphinium - and painted black (or something definitely obvious. There's no need to hide them if they're interestingly made)?

Or an old sewing machine frame or wrought iron table base/chairs in interesting rust, or discreet, or gaudy paint?

Or brush cut as supports for garden peas? Or, if your garden is 'rustic' - driftwood and rocks. They definitely go beautifully with both.