I have been collaging for the pasts three years and tend to use old National Geographic magazines. I usually start by finding a strong image and having an idea of where I can take it. Depending on the material I use scissors but there are times when you need your X-acto knife, so knowing how to use it comes in handy. After I have my material ready I pull a glue stick or some spray adhesive if the material is delicate. Once the paper is glued I trim off all excess paper and make sure its a nice square or rectangle.