Not a technical skill, but in the self improvement genre - Colin Murray’s channel https://m.youtube.com/@colinmurrayYT/videos is great for people who like exercising from home, without investing a lot in equipments and weight. Has helped me exercise more regularly compared to past years.

And then for one of my hobbies https://m.youtube.com/@idaemonplasmo for building better model kit aircrafts.

Not sure if they are masters of their craft, but they make their craft more accessible/enjoyable for me.