I've had great fun with this.
He Wood Silver Wind Wood + L'Instant de Guerlain Pour Homme Extreme (2:1)
Wonderful evening scent, adds a bit of woodsy powder to the Guerlain's enveloping cacao drydown. Elicits a stronger response from women than anything else I've worn before or since.
He Wood Rocky Mountain Wood + L'Eau d'Issey Pour Homme (2:1)
Great for a brisk yet sunny spring day. The Miyake's sweetness is tempered by a smooth vetiver bite that stands out but still melds well with the yuzu due to its creaminess. Just be careful to be sparing with the Miyake; it can take over before you know it.
Animale Animale + Michael Jordan Legend (2:2)
The concentration here might seem high, but I find that both these fragrances' bottles have subpar sprayers so two sprays of each are needed to get any decent amount of liquid out. If your bottles are better, consider it a 1:1 instead. There's something in Animale's top that sits uneasily with the full-on sweetness of Legend, but about twenty minutes in, everything blends together into an incredibly singular accord. This is a sweet and funky date night scent, really quite remarkably unique. Would not wear this casually.
Live Jazz + Terre d'Hermes (2:1)
Sweet, dirty, sunny, fresh. The perfect thing for an outdoors party on a summer evening.
Edit: Almost forgot this flat-out amazing combination:
Eau des Baux + Aventus (1:1)
The incensey woods of EdB and the pineapple sweetness of Aventus are truly a match made in heaven, and later on they switch places gracefully as Aventus transitions into musk and woods while EdB turns up the vanilla. This combination is absolutely incredible, and it elicited an amazing number of positive reactions. Just be careful to not overdo it, since these are both relatively powerful scents. One spray of each is plenty.