Save all those scraps from your favourite papers as they will come in handy. You can cut them up into small circles of various sizes(don't worry if they are not exactly round), crumple them up, distress the edges(I tear little rips at intervals around the edges and distress with some ink), layer these on top of each other then split pin/brad to hold together.
They are easy and use up all those scraps of paper too.
GO ON HAVE A GO!
See the gallery for more ideas.