What are the most helpful First Aid techniques you can use to save a life without having to use materials?

you are right, the heimlich and cpr is good to know, and it is good to have at least a basic understanding what to do's and what not to do's. you need to know to put pressure on a wound, elevate the feet, the general stuff. it is good to know early signs too. know the abc's (airway, breathing, circulation) if you can, learn more. i didnt have much choice on the matter- my parents were EMT's, firefighters, first responders, police... all of that... they used to go to their classes, and i would get to watch when i was little. i am glad of all of this, because i never know when i would need it. i hope i answered the question well enough!!! -Angel-

It is entirely possible to do most first aid and CPR without any tools or supplies. I need a few basic materials I can scrounge for splints, and clean fabrics make bandaging easier, but I can use a lot of fabrics in my surroundings for that.