Any suggestions on how to achieve this already are welcome.
It would be nice to have a layer that you can draw notes onto. Mark areas on/off the canvas.
I can't find a way to annotate anything in the layout. Nothing complex a pen,straight line and a choice of colours will do.
It would also be nice to be able to choose from a blank layer or a grid, as unless I'm missing something (although you can turn on snapping) there is no way to actually show a grid in the layout.