Benefit Puff Off
Honestly, the only products we've ever found to banish under-eye puffiness - something you lot fret about constantly - offer some kind of 'physical action', to smooth away fluid from under the eyes. (Which in most cases is what puffiness actually is.) So: while not quite on a par with oo1 London EyeCicles (read our slightly gobsmacked review here), this nifty little make-up-bag addition from Benefit is definitely good for on-the-go face-smoothing. It has a metallic dispenser (we love that they call it a 'smooth-o-matic glide' which you can use to iron away the built-up fluid. The cooling action of the metal helps, too.
The product itself is an eye gel (also cooling), which you tap or smooth into skin - though we've a hunch: it's that 'ironing' action which does the trick.