We have finally got the "little room" (as we call it) working as a functional office/spare bedroom. It really is a little room, just 2m x 3m - hard to believe this used to be the kitchen - but it's perfect for a cosy workspace.
The desk is H's grandmother's old sewing table - to get a bit more desk space, we just added a board on top that we painted white. The shelves above it are leaves from H's grandparents' old dining table (the table was given away to a relative long ago, but the leaves were still kicking around in the shed), fitted with brackets from the hardware store. A couple of regular old Billy bookcases (gotta love Ikea) hold all the "stuff". I put doors on them to hide away the mess and make them look a little prettier.
The single bed is also from Ikea - it was my couch/guest bed back when I had my studio apartment. I'd like to add some more cushions for more of a "daybed" feeling, and maybe make a nice woolly throw for it too.
I am still getting the hang of using this room on a regular basis though - I tend to default to the kitchen table or the couch to work. But I'm in here now as I type, and it's so lovely and bright and peaceful. I foresee spending a lot more time here from now on.