The tone thing is something which comes up quite a bit of the Charlie Francis website, and in his books. For me, its something thats quite hard to monitor myself, and so I dont really bother thinking about it, as its just something else to worry about!
Quite often, the day before a one off-race (i.e. a GP), I will do a jog and drills. I have found this prepares me better for the comp, but couldnt think why. Maybe it has a good effect on tone.
Comparatively, I do usually train pretty hard 2 days pre-comp, usually doing blocks!