Recycling felt pieces

I like to try lots of different fibres and experiment a bit, so I often end up with quite a few sample pieces or pieces of felt where I like the technique, but don't think the colours worked.
A while ago I made a collage from some of the sample pieces and I really liked it. So when I realised I had quite a lot of sample pieces again, I thought I'd make another collage and this time combine it with my latest obsession-notebook covers.

This is the finished collage piece:

And this is the Notebook cover I made from it:

I measured, and cut out a piece of craft felt to the size I needed before sewing on the felt pieces with 'invisible' thread (like thin nylon beading thread). I also added some handmade yarn scraps. I had intended finishing it off with blanket stitch around the edges, but all the sewing shrank it a little.