I would likely say. Experience is the key for that. It would be hard to do anything by just watching tutorials(tutorials do help too). you need also know how the joints work.
Also when i parkour i do not use youtube run or something but i make a run for myself. You can try youtube run but after like 150 frames your likely going to fall down so it means you have to manage it by yourself. Why i would likely fall? Because The Rectangle object are not absolutely Perfect, So try yourself to run on Rectangle Objects and The ground you may spot difference in your run. So when you parkour just don't stick on same moves "manage" it to work perfectly.
Summary: When you parkour always manage your run. Practice until nearly Perfect
So final word "YOU" are the best teacher.