I recommend that a mix of martial arts and self defense styles from various countries and different cultures can diversify your fighting skills. No matter what your body type, these styles of combat can increase your fitness and muscular endurance getting you prepared and ready for any time violence starts. This is the benefit of being able to learn martial arts!
A lot of people wonder if the modern day black belt teaching the self defense and martial arts styles are actually equipped with real life or death experiences. When you learn martial arts you have to realize that they are designed to protect you from attack, and if you are just being taught theory and rehearsed drills with no combat application you will greatly suffer.
You need to understand fight psychology and the elements of stress and fear as well as the pain of recieving of shots. Your stress levels will climb but being able to perform with the set drills and tools to defend yourself with various strikes while being calm is essential. In a street based style of self defense you want to learn martial arts that include dirty fighting, pressure points, street fighting and more.
I recommend from personal experience that you incorporate different types of martial arts styles and design your own combat system based on your skill level, your body type, your size, your range of speed, your timing, your instincts, and your abilities acquired through training.
In a real life or death you want to use hardcore aggression and be the aggressor in a real life or death attack. Don't forget to block and defend but primarily focus on attacking as hard and as vicious as you can. I recommend you look into and learn martial arts that contain different elements of combat. Absorb and memorize these techniques and use them as part of your arsenal for fighting.
To make things flow easier grab the best techniques from every style through taking classes, or absorbing them through books, online videos and of course actual physical practice. Remember that in a street assault there is no such thing as Hollywood style moves that work.
