I've done this route several times. Route Brentwood -> QE2 Bridge -> Bewl Water -> Brighton Marina and you can't go too wrong airspace wise. They're all pretty easy waypoints too - Stapleford used to give it as their PPL QXC route.
Shoreham village itself is nice and quaint, and walkable from the airfield. The terminal building is also of interest, with a decent cafe and views of the ramp, and don't forget to look out for your own arrival/departure displayed on the screens in the terminal!