This depends on personal preference. The two main choices are a poly finish or a tung oil finish. A polyurethane finish will give a clear hard surface coat that protects the surface more and provides a glossy coat. This finish is more labor intensive, requiring several coats with sanding in between. A tung oil finish is a lower maintenance option that soaks into the wood itself to protect it. It can be simply rubbed in with a cloth and does not require sanding between applications, but it does not provide a hard surface finish. We don’t recommend any one brand of finish—there are so many good ones out there. We recommend you consult with your installer and patronize your local supply store.