They were quite labour-intensive! I first went through all my old magazines and cut out and pictures with interesting colours, patterns or textures. Then I tore those into small pieces and sorted out by colour. I sketched basic designs as a plan, then pasted each torn up piece individually on to the postcard using Clag glue. With two of the postcards, I was losing motivation and inspiration with the mosaic style, so I instead, I pasted larger pieces in a patchwork style, with little pictures on top, using colours as a theme.
In the end, I'm pleased with how they turned out, I haven't done paper craft since highschool/uni, so it was a new craft method for me. I have always loved mosaics and that was obviously a big inspiration for me. I will post them out today, my postcards are going all over the world!
There is a Flickr group if you'd like to see what other people have been creating!