Fiona was the first name that I fell in love with as a child, when I was a budding name nerd. I still like it but it's not one of my all-time top names any more. A couple of real-life ones have put me off it a bit. It's a bit dated to me as I know a few in their late 20s and 30s if not older. I certainly don't think of Princess Fiona, but that's not a terrible association. The only downside is that Fionas tend to get nicknamed Fi which I hate!
I'm rubbish at coming up with combos for other people. Fiona Miriam works though as does Evelyn Fiona. Fiona Evelyn would too, I think.