Depends what type of surface it is but if it's concreate slabs I tend to use 1:1 mix roughly 7% in a window cleaners bucket.
Wet all the area down first including boarders, plants and grass where the runoff might go with a garden hose first.
I find the simplest way is to use a deck brush or cheapo car/truck brush and slap it on and brush it in.
Let dwell for about half an hour making sure it remains wet and don't dry out.
Scrub stubbon areas with a deck brush and re-apply if needed.
Then just rinse off with a garden hose.
Hypo at that streagth is nasty stuff to handle and use so wear ppe eye protection, gloves, wellies and old cloths.
Keep pets and children out of the area whilst still wet and don't let anybody walk through it either as could be tracked back into the home. Don't use it if there is a pond nearby either as the runoff will kill anything living in the pond.
If a pet should walk through it the get the owner to dunk it in water so it don't damage it's paws etc.
Likewise footware should be removed and washed when going into the house if someone in the household decides to walk through it after you told them not to.
No matter how many times I tell people I end up running after pets and telling off the owners for walking through it too.
It's harmless when the surface is dry thank god.
Mixing trade tip: add the water first before you add the hypo as it can splash and make sure you wear safety glasses as you don't want that stuff going in your eyes. Also wear chem resistant glove to protect your hands too.
I don't like to spray it on as being a spray can drift anywhere even in the lightest of winds.