At the end of the year I usually round things off with a bunch of photo studies of landscapes, cloudscapes, wide open spaces in general. It's incredibly relaxing as there are no big decisions to be made about theme, colour palette or composition - I just put together a collection of reference photos and work through them.
I worked on these four at a time, switching between them when I find myself treading water and noodling around instead of making real changes and refinements. These are my favourite four out of eight.