haha, that is asking a very broad question. Tastes definitely vary on what clean and stylish would be. I like the Silverado tail mine has with the brake light with grills on the lic plate bracket on the side.
Instead of looking for "custom", look for bobber, cafe racer, or cruiser. This should narrow down your search options a little. I also found just looking up V Star Taillight in images brings up a lot of different ideas. After you get your idea of clean and stylish narrowed down you can start looking in to how they got their bikes to that point and adjusting from there.
Good luck and have fun with making it yours.