I guess it's been a while since anyone posted on this thread but I just saw it and was interested in it. I hope that's okay!
It was easy to pick my engagement ring. My DH didn't have one with him when he proposed. Basically he came to my house and asked to talk to my father and they went off together and when they came back I learned that my DH had asked for 'my hand'. He then got on one knee in front of me and proposed and I said yes. He said he was sorry he didn't have a ring, but that he had thought I might like to pick it out myself and would I mind going together with him to the jewelry store. I didn't mind. I thought it was nice that he wanted to get what I wanted.
I guess I should mention here that we had been dating for seven years at this point, and I really, REALLY wanted to get married to this guy. (We started dating when we were 18 and got married at age 25). My big criteria for the engagement ring was that I wanted one as soon as possible. I just wanted everyone to know that I was FINALLY engaged. (My mother and aunts had been nagging me about it. In my culture, at that time, 25 years old was very old to be still unmarried). So when we went shopping for the ring, my biggest criteria was to walk out with a ring on my finger THAT DAY. My only other criteria was that the diamond should be the biggest one that we could manage that was still shiny and 'pretty'. I knew nothing about cut, color, clarity, etc. and neither did DH.
This was in 1982 and the only choices in the store were solitaires set in YG, which helped to simplify matters. Nothing had sidestones, there was no pave, none of the bands had diamonds inset in them. It was all very plain. The only real choice was between getting a round brilliant or a marquise (marquises were very popular back then). I think they had some emerald cut, but those were very few and I 'm pretty sure that the princess cut was not even invented yet. I decided I wanted a round brilliant, I started looking at the sizes, I picked out a few and DH told me which ones were in the budget. Then I picked the prettiest one out of the biggest stones left. DH paid for it, in cash (most people did not have credit cards back then and he didn't want to finance it). And out we went.
I was so happy with my ring and have remained happy with it. Only my wedding band, which exactly matches DH's and is engraved inside (and was blessed by the pastor at my wedding) is more important to me. That is a YG band with a WG edging.
Fast forward to last year, when we had our 25th wedding anniversary. DH decided he wanted to get me an anniversary band. This time, with the internet and such sources as Pricescope and sites like Blue Nile, I did all kinds of research. I had learned about color, clarity and cut in the meantime, and of course there was a huge amount of choice out there. Although, interestingly enough, many of the 'new' rings looked a whole lot like my grandmother's engagement. Which was a white gold filigree art deco ring with milgrain and so forth. In 1982, when me and DH went ring shopping, I wouldn't have wanted that. It was so 'old lady' looking at that time, so out of date, that I didn't appreciate how pretty it was. It's funny how things go in and out of style.
Anyway, to make a long story short, I did all this research this time and had a lot more knowledge but my criteria remained exactly the same, after all the years that had passed. I still wanted to biggest diamond that DH could afford that was 'pretty'. That is, white and sparkly. I ended up going for a round brilliant again, I guess because they are the sparkliest. I went very high color, F and I got the most ideal of ideal cuts, an AGS0. I got it from Blue Nile, where I had the choice to design my own ring, looked at millions of choices and ended up with--guess what? A setting that is just about identical to that of my engagement ring. That is six-prong Tiffany and the anniversary ring is four-prong tiffany. I changed the metal to platinum, mostly because it is a white metal and that seemed right for a silver anniversary ring, and I went a teensy bit more ornate--there is a little milgrain edging on the plain band.
I guess I liked classic and simple years ago and I still like the same thing, even when there is a lot more choice available. Funny, isn't it?
With both my rings, the engagement ring and the anniversary ring, I like that I can use them just as they are, and showcase the diamonds. I like that I can make them look different also, when I want to. I have an enhancer which makes my original ring look like a three-stone and I use that sometimes. I have a couple of eternity rings that stack that also change the look of the rings that I put on when I feel like it. I know there are other kinds of enhancers available, also. When you buy a ring, you might find that that versatility is something to consider.
Round brilliants look great on the kind of fingers that I have. I do think you should try on different types of stones to see what flatters your fingers. And maybe sparkly isn't important to you, so you might prefer some other type of stone, like an emerald cut or asscher, which doesn't sparkle much.
Anyway, good luck. And remember that the man who is giving it to you is the main thing. I would hate my engagement ring, no matter how beautiful it was, if I wasn't with my DH any longer, instead of still happy after 25 years. Sometimes I go to pawnshops and its really sad to see the rows and rows of engagement rings. It makes you think.