Checklists - Pressure Washing

Greet the customer
Take pictures of basically the whole house but make sure to really document up close any major issues (loose, burnt or dead)
Check for oxidation in high sunlight areas and be careful not to apply too much pressure to those areas
Test potential problem areas in an inconspicous spot thoroughly before doing entire area

Spray vegetation down with water for effective dilution of any runoff that happens to hit them.
Move the downspout extenders out a couple of inches so that any runoff into the downspout goes into the dirt and doesnt get pushed against bushes
Try to find any place that you can dilute the runoff
Move the downspout extenders back into their normal place
Spray the vegetation with water once again