The answer is threefold: start at the top, use masses of dropcloths, and spray. You need to start at the top because Gravity will pull any spray or drips downwards onto a deck below; you don’t want to be putting a dropcloth on a fresh deck because it will leave remnants on it. You want to use lots of dropcloths against the walls and everything below and along the ground for some way because overspray can go far. Be careful, also, of oilbased stains which are so thin that they will travel along a dropcloth and then slide underneath. Also, oilbased finishes will stain stone and concrete for many years with a single drip; so be very careful with the dropcloths! Lord help you if you kick a whole can over! Obviously skip windy days. Finally there is no way you can get a neat job and done without vast time by handbrushing; the answer is to spray. Considering the complexity of spraying handrails above stone and walls, we did it very well and it looks lovely, without spills or drips.