I like simple, and that's exactly what your truck is. I love it. If it was my truck, I don't know that I'd do too much more to it, but it's no my truck, it's yours.
One thing I *would* do is a tonneau cover. I'd probably go with one of the vinyl roll up ones. That way you can still put stuff in the bed during wet weather, and you can roll it up when you want to carry something that won't fit under it. I might also add a bed liner, if it doesn't already have one.
Some people like window visors on the door windows. Yes, I do think they look good. I'm not sure that I'd put them on my vehicle, though.