What’s the easiest way to make any room look better? A vase of fresh flowers.

It’s also one of the least expensive ways — if you have access to a garden, a yard or a container garden on a balcony.

Assembling flower arrangements like the ones you see in magazines or on social media doesn’t have to mean spending a small fortune at an upscale flower shop, where they do the arranging for you. A simple grouping of flowers, branches, leaves and even vegetables can look equally appealing.

“You don’t have to grow, like, 5,000 peonies,” said Christopher Spitzmiller, 52, who designs lamps and ceramics. “You can put a single bloom in a flower vase, and that is often enough.”

As it happens, Mr. Spitzmiller has an enviable garden at Clove Brook Farm, the Millbrook, N.Y., home he shares with his husband, Anthony Bellomo, the owner of Orangerie, a garden shop. But they agree that simpler can sometimes be better.

“We’ll often put kale, chard or leafy greens that you would eat into arrangements,” said Mr. Bellomo, 45.