We thought some sort of plan was essential, though I guess doing anything fancier than a 'fag packet design' was optional. There was going to be a lot of bits and if we were doing it all together, working out how it would all fit was worthwhile, if only to avoid the hassle of something not working in the future.
Before starting I spent many an evening drawing pictures of how I thought it might look, where things could go etc, all based round the basic pics and specs the manufacturer provides, some of these are below, and then reviewing them together to see if we could see it working.
The layout above was made on just a basic computer spreadsheet working on a 10cm=1 cell basis and colouring them in. I did look at some of the computer drawing programs but couldn't get any of them to provide the easy design that a pencil and paper gave me. I've attached the spreadsheet as well.
The plan had to have the basics.
And some extras