Make sure you don't wear too much stuff over the baselayer that's non-breathable, or you'll sweat too much, and despite the baselayer 'wicking' away the sweat, you'll get too wet under the non-breathable stuff. As it should be fairly cold on the night (and will 'feel' cold), it's especially important to feel slightly cold at the start and not too warm, warming up as you go--if you get too hot, you'll sweat too much, trapped sweat will turn cold, and you'll feel uncomfortable.
Make sure you don't wear too much stuff over the baselayer that's non-breathable, or you'll sweat too much, and despite the baselayer 'wicking' away the sweat, you'll get too wet under the non-breathable stuff. As it should be fairly cold on the night (and will 'feel' cold), it's especially important to feel slightly cold at the start and not too warm, warming up as you go--if you get too hot, you'll sweat too much, trapped sweat will turn cold, and you'll feel uncomfortable.