Double exposures have been around for years, but they seemed to disappear when digital came along. But Nikon DSLRs have had the capability for over a decade now, and Canon have recently started implementing it, too. It’s a fantastic technique to experiment with, although it takes a lot of practise, skill and a little luck to really get the results you’re after.
To help make things a little more reliable, though, you can also make them in Photoshop. This video from Chris at Spoon Graphics walks us through the whole process. The tutorial actually came out a couple of years ago, but seems to have recently become popular again. And it’s a great way of achieving the technique.