Always burn incense in a proper incense holder on a stable surface. The surface should be flat, uncluttered, and resistant to heat. Avoid placing incense directly on timber furniture, bookshelves, fabric, paper, or anything that could mark, melt, or catch fire.
A dining table, stone bench, ceramic tray, or clear side table can work well, as long as the incense is not close to curtains, bedding, paper, dried flowers, clothing, or open windows. Moving air from a window or fan can push ash sideways or make the ember burn unevenly.
If you live in a smaller apartment, keep the setup simple. A holder, a tray, and enough space around the burning stick are more important than styling the area beautifully.