Smart: I'd wear this look for work, basically just a lace shirt from the New Look sale a few years ago, with some black jeggings and the Allegra boots from Topshop. For cooler days, I'd pop a blazer over the top.
Night out: I'm not one for dresses but this is a real old staple in my wardrobe. It was about £13 from Primark and I've worn it to death but if I ever need to 'dress up' I have this as an option. I just paired it with a nude bag, some black tights and black suede wedges.
This one is a bit of a mix and match outfit, I'd personally wear this out at night or for dinner out, or I'd throw on my converse and denim jacket and go shopping in it. These lace leggings are so versatile! If you don't want to go for full on lace, you could go for a hint of lace like the picture below, with some lace edged cycling shorts.
How else would you wear lace?