DIY HIDE TV CORDS - Remove tv from mounting bracket & set aside. Locate area for cords (make sure they are easily accessible, but hidden by tv). Use drywall saw to cut hole. Cut another hole directly below 1st hole toward bottom of wall. Use fish tape or stiff wire to bring cords up thru wall. There are now a variety of products available to give a prof look-buy them 1st to ensure proper hole sizes! Hook up & re-mount tv!
If you have a mount for your TV, fasten all of the electronics with the unsightly wires to it. (If you need to, build a small lightweight frame to attach to your mount.) Bundle up the wires as much as possible before fastening them to the mount so they don't get tangled once they're up there. Use bungee cords to secure heavier hardware like a cable box or router. Plug everything into a power strip so you only have to worry about one wire running from your TV to the wall.