Creative Option Mounted Rustic Shelves
There are quite a few creative options to do with mounted rustic shelves, such as the type of wood to be used. Pine is a cheaper option if you want to use paint or clean stain. The oak is good to use if the budget is larger and you want to use the clear stain and polyurethane so see the natural grain of the wood. Cut each shelf to the desired/required length with saw power.
Remove all chips with fine sandpaper, always sand with the grain and not against it. You can also lightly sand the edges so they are softer to the touch. Mark on the wall the desired positions of your rustic shelves diy. Then at each mark put a level of alcohol against the wall and run a pencil line on the edge of the level. If you have more than one shelf to put up, you have parallel pencil level on your wall.
Run a stud locator along each line and mark the position of each of the wooden posts. Now choose if you install the brackets on the posts closest to the ends of each shelf, or install also one or more of the mid-wall studs. If your rustic wood wall shelves will keep heavy books, it is better to have at least one support in the middle, as well as at each end.