My garage has seen way more cars with botched repairs from online how-to videos this year. It's a whole new kind of job. | Auto Mechanics - Opinions Matter
Rayb82 has it right about starting with smaller jobs. I saw it happen to a neighbor last month. He watched one video on brake pads and ended up having to flatbed his truck over here when the caliper piston shot out. That false confidence makes people skip the simple stuff and jump right into a real mess.
Tell people to watch a few different videos first, not just one. Gets 'em a better idea of what they're actually doing. Also, maybe start with smaller jobs to build confidence, lol.