It’s in the details

As well as altering your framing, think more abstractly. You don’t have to include the whole body or surfboard in your shot; fill the frame with fragments. The reason why this shot works is because the surfboard is out of focus but recognisable. It adds to the scene without overwhelming it. Also note the leash on the board and round the ankle – even without the whole leash running through the frame you can tell the model and board are linked.