Ok, so I'm cheating a little bit here as this isn't technically a 'duo' as there's three products, but I couldn't think of a word for 'three things' that sounded right :p I think these products look so beautiful together and make a gorgeous combination for Spring and into Summer too.
I picked up MAC's MSF in 'Gold Deposit' recently and it's (for my lighter skin tone) a combination of a bronzer and highlighter. I can use it on the top of my cheekbones super lightly to give a really authentic sun-kissed look, and I have a feeling this is going to be a staple product once my summer tan starts developing!
This Dainty Doll blush in '004 - You Are My Sunshine' (cute name!) is a peach with a subtle gold shimmer running throughout it and is simply a beautiful colour.
Finally MAC's 'Costa Chic' is a coral lip colour that's just perfect for spring. You can apply it lightly or more intensely and it looks amazing either way.