I find making collages fascinating.
One interesting technique to glue your items to the base is the so-called beeswax collage (for links to tutorials see Links below). It gives a warm colour to the collage and if polished a nice shine too.
On the photo you can see my first (and up until now last) attempt to do this. I collaged pieces of different newspapers (Chinese, Arabic, Corean) and self-made papers and than embroidered the spiral by hand.
Links:
At ARTchix Studio: Beeswax Collage: the link isn’t available no more.
At art-e-zine: Beeswax Collage
Google search results for ‘beeswax collage’
Google image search results for ‘beeswax collage’