My works (last year for my BOW) were, in a way, collages. Not in the "total" collage sense that Hoch uses, but more simple and minimal. I pulled together images and the theme of life's journey on a number of canvases of various sizes (small to large).
Maybe look at a collage as a sort of mind map. It's the collection of thoughts (ie images) you feel are related to travel.
Below is one of my own works (favourite lol) .. click for bigger image.
As you can see, I have incorporated stenciled text, magzine words/images and a photo. I also added 'graphic' details. The construction of a collage is really up to you, the creator. Don't be afraid of trying new 'styles'. If you're really afraid of 'wasting' an image you've found, make colour copies of it and play around with that. That's what I did to begin with.
Remember: "Don't be precious" and "Just do it" ... my artistic mantra