Alot of people who put their first coat on their models use paint and paint brushes. Now that usually will take a bit of time. But if you use a nice black spray paint it will be done in no time and you will not miss any spots.
now you want to put your model(s) face down then lightly pray over them.
if you want to get them done quickly put them in a group all face down first and spray over them for a quick result.
flip them over and do the same thing to the front of your models.
let sit for a while and they will turn out like this.
hope this was helpful for some people.