Hi Tony,
When I'm building clients layouts I fit the point control after laying and wiring the track. Then I test everything. The next stage is to airbrush the track in sleeper grime, then fit the dummy point motors along with signals and Yard Lights as these look better ballasted in.
I also start basic scenery before I ballast such as plaster bandage as this can be very messy and difficult to remove from ballast.
Then ballast and I go over the track with the airbrush and lightly weather the ballast. If you weather the track after ballasting without painting the track first the ballast looks too dirty and typically ballast is quite clean unless it's a yard or siding.
Ultimately it's personal choice and rule 1 applies, it's your layout, your rules!