Hi dunni73
I used very few post-its and only because i thought i should !
In the end i pointed myself to issues i thought i may need to refer to in the viva. For example, where i describe why i did something "controversial", where i quoted a key source and most important where i described my contribution to knowledge.
In fact, i only used one.. and it was a note on my research approach. "They" didn't like it, didn't agree with it and didn't think it fitted.. i was able to explain why and then refer to the page, quote from Professor Big as to why it was appropriate. Made me feel good :-)
As with most things it is the act of thinking about what the examiners might ask which is useful. Doing something practical at this stage is nice too, its so frustrating isn't it.
Good luck with your viva. Chuff