In DIY, there is a wide array of tools for performing all sorts of fastening tasks, and this is especially true in carpentry. To join wooden elements, one can use wooden dowels. These types of tools are made of wood so they can blend more easily into the elements where they are embedded and thus be more discreet.
For your construction of wooden structures or furniture, you can use wooden dowels in addition to the usual nails. For a better visual result and a more eco-friendly option, wooden dowels are available like the Festool dowels. When chosen correctly, these can blend into the structure and will be hard to spot. In addition to their ability to join wooden elements, a wooden dowel can also be used to hide perforations in your materials. You just need to choose a wooden dowel of the same shade, same wood, and same size as the hole you want to fill.