I then sewed the vertical sashes and the panels together in groups of four.
I then sewed the horizontal sashes to the corner stones and joined all the pieces up.
The second snag is that the piece is a little too long and thin for my liking. I could have arranged the panels in a more square formation but that would have left me with 4 unused panels (ie 5 by 5). So my idea to fix this is to add an extra border just to both sides, not the tops, to widen it out. I think I'm going to do strips of matching fabric sewed in rows.
1. buy extra cream fabric for borders