As in, channels where the presenter is laid back, calming, and the content is slower paced and chill. My go two examples are LGR for retro computer stuff, and Hainbach for experimental tape music.
https://www.youtube.com/@essentialcraftsman is just a guy building houses and doing iron work. Very cool.
I saw a lot of channels that sprung to mind already posted. But I want to strongly recommend Thomas Shahan for super chill bug photography and mellow voice overs. Worth checking out even if you’re not into macro photography.
bigclivedotcom - I have no idea what he’s talking about 90% of the time but he’s generally a relaxing watch.
Ali Spagnola and Aging Wheels aren’t quite what you’re describing in terms of being calm and chill but I still love their stuff.
Seconding others’ recommendations for Technology Connections, TheCrafsMan, Cathode Ray Dude, and Techmoan.
“Tally Ho” comes to mind, where a guy turns a famous wreck into a boat.
Baumgartner Restoration. I watch it like bedtime stories.
I like this channel Workshop Companion. He also looks exactly like the kind of person you want to go to, to ask questions about carpentry.
Attoparsec, Chronova Engineering, and polymatt all fit that description.
I mostly watch guitar luthiers on youtube nowadays as a background for when I do stuff like washing dishes and such, so I don’t want to listen to people yelling.
My favourite channels are twoodfrd and Doug McCormack for this reason exactly: they’re laid back, constructive and politePask Makes - Australian wood- and metalworking guy who does the most elaborate and intricate things with absolute chill.
Dashner Design and Restoration - also woodworking, finds old and neglected mid century modern furniture at thrift stores and restores them beautifully.
Maybe tangential but FutureCanoe - meme-y cooking channel, super relatable and relaxing mostly because his voice sounds like existential dread.
Most of what I would have suggested has already been posted by others, but I can say Kruggsmash’s Dwarf Fortress stories do this for me. The Waddlesquash/Kingdom of Autumn series he did (with the pumpkin mod) is particularly laid back, but even the action-heavy series are calming to watch/listen to.
Thomas Johnson Antique Furniture Restoration
I know there are a lot of restoration channels out there. Most of them annoy the fuck out of me.
Tom Johnson has the skill and experience and really takes his time to restore wooden furniture without trying to make it look brand new. At the same time teaches some of his skills in a calm and composed as well. But sometimes there are loud machine noises.
Joe Pera: https://m.youtube.com/@JoePeraComedy In theory comedy, but the most wholesome relaxing kind you can imagine.
WAY OUT WEST with Sandra and Tim, Kind of a farm / homestead in Western Ireland. https://m.youtube.com/@WayOutWestx2
Pretty much exactly Bob Ross if he were a nice Canadian lady doing nails…