white wash is watered down paint start with a half a gallon to a 1/8 of water and keep adding till you get the right consistency you could also get recipes on the Internet

Rockin Fine Finish is definitely the expert. My amateur approach is to conduct a test run in the most inconspicuous place as possible, preferably on test materials if you have extra stone/brick that matches the material to be painted.

Because it is much easier to strengthen a finish, i.e., add a second coat, I start by erring on the diluted side--i.e., more water--and then up the ration of paint if the mixture is too dilute. IME, it is much easier to add a second coat to get more color, than erase a coat with too much color.