My husband bought mine without any help or hints at all. He knew I liked diamonds, and only wore white gold, so that was a good start. The shape has 2 special meanings for us that is why he picked it, which was wonderful.

I think it depends on you and your relationship. Perhaps test drive a few so you know what you do and don't like, then you can casually comment when you see some - either in real life, or on tv or in mags. Hints like "that's a beautiful ring", "I love solitaire diamonds", "rose gold is my favourite" etc etc can give some guidance if it is somehting he is thinking about.