I was very specific about the style of ring I wanted, so even if my fiance had chosen the ring himself, he wasn't going in blind. I didn't want a diamond and I don't wear much gold. I wanted classic but not traditional. And I wanted an aquamarine, but definitely not a sapphire. I'm difficult to buy for, basically. Give your partner all the help you can, this isn't some sort of test they have to pass. I'm talking links, pictures in magazines, emails with "ABSOLUTELY NOT THIS" in the subject line. You're not ruining the surprise, you're making a really difficult purchase a lot easier.