The final challenge was to use a technique by the lovely Karyn.
And this is what I came up with. Lizzy is always encouraging me to have a go with mixed media. She did mention this particular technique (as well as using bubble wrap, which is next on my list of things to try) so away I went.
I used D-Lish Scraps wood veneers. I also used a very pretty Studio Calico sticker sheet.