The Way Beginners Should Start Learning Straight Punches

In most combat sports like Muay Thai, Boxing, MMA, Kickboxing and even Karate straight punches have a "Corkscrew" (turning the thumb down) on straight punches and this video explains the bad habit that learning a corkscrew too early can result in, how to fix it and shows how most beginners should learn and throw their jab and cross in Mixed Martial Arts.
Even if beginners don't start by throwing their punches this way it's important to know the concept in order to help avoid problems with the "corkscrew" which primarily is to avoid telegraphing your punches and making it easier to land punches on your opponents or sparring partners.