Most wood holds have no finish to them other than sanding or some have a sort of griptape added to them. If you only sand the holds to about 120 grit or less you will have a hold that is a bit rougher and therefore easier to hold. HOwever sanding it to 600 grit or 340 grit would make it super slippery. Different types of wood have different grip levels as well. Something super hard and fine-grained like walnut might have slightly less friction than say a softer wood that is not so tight-grained. Adding texture with like a dremmel can also help but this is sof course reliant on you not butchering the hold. I really like wood for wood's sake. In that I want the slippery texture of wood because it forces me to squeeze. To sort of find a nice middle ground so I don't get too annoyed board climbing I make my edges a bit more generous so that I feel like my fingers arent going to constantly slip off and leave me on my ass all the time. One other big point no one really talks about is the size of the lip of an edge. A lot of holds, such as from Taylor made are really nice, however much like the lattice rungs the rounded nature of the edge makes holding the hold a lot harder, which great for some walls, but my wall is 55 degrees so makes them a huge challenge. It may technically be finger pad but in reality its less as your finger cant get enough purchase due to the slopy nature of the edge. I try to make my edges as sharp as possible to avoid this.
