Before we begin, Lemme state this: I painted my window frames prior to taking these pictures, and writing this thread. I am not a professional, but Mine did come out nice looking.
Things you will need:
1 Can of spray primer
1 Can of spray paint
an old newspaper
a roll of masking tape
a scotchbrite pad or something similar (not shown)
Picking the right primer:
Before you choose a primer, you are gonna want to choose paint. Now the automotive paint will work the best, But most paints will do just fine. If you pick a light colored paint, then you will want a white primer, for a dark colored paint, you will want gray primer, if you chose a black paint, then you can use gray or black primer.
Now that you have your supplies, you need to prepare your surface. You should wash and dry your window fames very well before you begin.

[hey, you can see my garage in them windows

]
Now, we gotta start
masking.
A little trick my dad taught me was to open up your door, and put a piece of newspaper halfway in the car, and halfway outside like this:
Now close the door (not too fast, or it will blow the paper out):
Repeat All the way around the top of the door:
Tape the corners of the paper down, also tape where the paper meets another piece:
Now, grab your masking tape and tape around the window, make sure that you take your time and do a good job. Tape all the way around the window.
now, get a piece of newspaper and tape it to the tape you applied earlier. Note: do not go right up to your painting edge with this rough tape
This is similar to 'tacking' in welding
if you come to a bend (and you will) simple fold over then edge of the paper, and fold it over again, to make a smooth-like edge. like this:
You need to seal the edge of the paper with masking tape all the way around, so that no paint gets under the newspaper. Like this:
Do the same on the bottom of the windows, and around the mirrors ect. make sure you cover the mirrors and anywhere else that is not covered around the windows.
Now, pick up your scotchbrite pad, and scuff the current paint, you do not need to press very hard, just make sure the paint is dull and smooth. Wipe the dust off with a paper towel or something similar.
Once you are all done scuffing, it is time for primer.
How to apply primer:
shake VERY WELL
1 light coat (very light coat)
wait for it to tack up so you do not get runs
apply 2 even coats waiting 7-10 mins between them
just make sure that it is all coated evenly

(yes that can is missing a tip)
Once your primer is %100 dry, you can start painting.
Use the same technique as when applying your primer, but apply one last coat a little thicker then the rest.
Once you are done painting, wait until the paint is almost dry, then remove the top layer of your masking (the newspaper taped to the original masking.
Once the paint is all dry, you can remove the rest of the masking:
And you are almost done, the final step is to GO FOR A DRIVE!
a. dries paint
b. face it you wanna show off
hope you enjoyed this. it took me a long time to write and i would really appreciate some comments.