SN3Guppy spells it out adequately. Preparation includes definition of the task to be performed (assuming it is of a professional nature), the desired objectives, performance limitations, overall risk assesment, contingency plans and a thorough "scouting" of the locale.
I never had the priveledge of trying dusting (would LOVE to), but flying inverted at 2 metres in film work, formation or during displays doesn't leave room for spare brain capacity (for me at least) to "make it up as you go along."
And yes, in such regimes of flight there IS a significant risk, and protective clothing/equipment could well save your life! I have seen it do just that.