Grind up the chile and add it to the salsa a little at a time, to your preference. When the salsa is completed, squeeze a lime on it, it will keep the salsa fresher longer and adds a good, fresh flavor. I don't use any specific measurements, but modify as I go. I usually start with a whole tomato and a half onion, then I add everything else to taste. Authentic Mexican cooking is more of an art than a science, it requires lots of tasting as you go, add more ingedients according to taste.
Salsa takes passion.