Main ingredients:
Tomatoes, preferably roma's. They seem to have the most flavor.
Cilantro
Vinegar
Lemon or lime juice
Hot Peppers
Sweet onion
And that's about it. All you have to do is chop up all the ingredients however chunky or liquidy you like, put in a bowl, and you're done! Nothing is ever measured so it's all about your tastes. Even better, right? I hope you enjoy!