Shop Together for the Ring
Who it works for: The practical one. You'd rather have a ring that suits your style than a big surprise.
How to do it: While walking past a jewelry store, casually express interest in stopping in and taking a look. Depending on the store, the salesperson will likely ask if you'd like to try anything on. A bolder option: Decide on a time to formally shop for rings together.
Timing tip: If he's a traditionalist, he may be opposed to shopping for the ring with you. If this is the case, consider going "window-shopping" with him, so that there's no pressure to buy while you're out together. That way, he can go back and buy the ring on his own.