The tip to painting a car "flat black" is to choose this paint.

1. prep the surface.. prime, sand with like 6-800 grit sandpaper.
2. take out the can and shake for exactly 60 seconds
3. turn the can over with the nozzle upside down and let out 120 seconds of air.. (this is so you have some control over the amount of spray coming out)
4. buy a can of "elmers glue spray adhesive" and take off the cap that looks like this.. you can take off the orange top and see if this cap is on there.. make sure it has an orange face.. we call these caps "rusto fatcaps" they spray extra wide, with a misted spray.. rather than the traditional cap that is on the cans. which spray in a hairy "dot"

5. Spray.. make LARGE left to right strokes that feather off on the ends. he last thing you want to do is at the end of the stroke to make a long stop.. paint will gob up and dri eather off like you are dusting Make sure that you are not TOO close to the panel when painting.. about 5 to 6 inches distance is appropriate. when you make strokes make sure each line is overlapped by a half of a stroke.. at first you will see SL drying streaks.. but the one hing that is different about Rustoleum is that it dries SLOWER than other paints.. so it will even out VE nicely.. but keep it in a place that nicely.. but keep it in a place that wont get too much debris.. not very necessary but it helps a bit..(Hint).. you can do a light tack spray and then go over it heavier but it isnt very necessary. I go the expanse of the car rather than panel by panel.. but you can do either.. ive done both with sim results should look like this..

This car was painted in a parking lot with only 5 cans of paint.
To get good at it i suggest practicing on an spare panel or just pull your balls out of your pelvis and go for it. and thats it.. Mr. Totem's flat black instructional post!