I don't like the idea of choosing rings together, it takes away the surprise and romance. If he proposes first though and then takes you to pick out a ring, that's better as the surprise is still there,but I loved that my DH completley surprised me with both the proposal and a ring he picked out himself. He has pretty good taste though, I guess if your guy is clueless in the jewellery department.....

Before we got engaged, when a friend of ours showed us her engangement ring, I told DH later that I loved her ring but preffred a flatter setting so it wouldn't catch on my clothes (the only hint I ever gave him LOL). By the time he proposed he knew my tastes well enough to pick out the perfect ring for me (white gold with a single saphire set quite flat in the ring, with a small diamond on either side). I love it so much more having had him pick it ut, I know it's really from his heart.