One product I used on the last build that I’m using on this one are the Click Bond swivel cable mounts. Easy to install with no fasteners and they will attach to any flat surface. If you buy them as a kit you get four mounts, glue, scuff pad and cleaner.
Place them where your expected wire runs will be, swivel the mount and run a cable tie through them loosely. Now run all your wires. When everything is finalized attach a final cable tie. Here are two aft fuselage walls with their cable mounts being installed. Great product.
