Gaylene, you are so right. The horizontal is important, too, and we seldom factor it in. Yet it really matters.
You and Staysfit are Una's and my "big sisters." Ha!!
Staysfit, I agree with you; we will wear similar style well. LUCKY you to be so tall -- lots of things will work on you that won't work so well on shortie me. Everything will appear more "square" on me vs. elongated and hence elegant on you. But in terms of necklines, I think we are very similar.
And if you see an item on me that you really like, you can pretty much guarantee it will also work on you. Unless the length of the arms or legs is an issue. Note that I usually have to shorten sleeves on jackets (not always, but often) and I also have to hem my pants (always, unless worn cuffed) and often my skirts. So if you're ever curious, you can always ask!
When I am in shopping mode, I look very carefully at WIWs and K/Rs by people who share my body type even if they don't completely share my style. Those that share both are of course a bonus!
People I watch assiduously for this specific purpose (among others, of course!) Angie; Karie; Sveta (more of an hourglass but has some similarities). Also Viva. Ceit (when she's around). All are taller than I am. But what fits and looks good on them will (with some exceptions) tend to fit and look good on me in my own size. And the necklines and overall shapes that flatter them will probably flatter me also, again, with some modifications for specific figure issues.
J. Crew tends to give you a terrific fit. It also works well on me as a rule. But -- get this -- I happen to know that Gaylene is also a J. Crew fan! Go figure. (I think she likes the knits, which give in the right places -- the sleeve/ shoulder).