...people showing how they frame houses, put soffits together, wire electrical boxes, repair plumbing, pour concrete, and all those sorts of things...
They video their jobs probably with hopes of creating more customers.
I watch some of those, because I learn things from them.
Mrs. bloke and I added on a 50 x 15 addition to our pole barn (where we do our work - as we built climate controlled rooms within it to do our work, when we first bought the property), whereas the addition is actually a shelter for animals that can go in and out of a pasture. It's pretty complex in it's features, and we built it well enough so as we didn't encounter any alignment problems with the original structure - though the land underneath the addition slopes in two directions. I didn't watch any pole barn videos, but simply studied the construction of the existing barn to understand how to add onto it. As far as lining up the addition with the original, being able to control things down to one or two thousandths of an inch in three dimensions (instruments) defined it as being pretty easy to keep discrepancies down to less than 1/8 of an inch from end to end when transferring those skills to macro. It's pretty nice, and features some lights, outlets, shelves, catch pens, windows - which line up with the existing windows in the building (so we can still see out), and a hayloft. Hey.. what we added on held up against a 100 mph straight line wind event.

what we haven't finished on it is a faux Cedar front which we are fastening on to a treated plywood front. It's salvaged 8-in fence boards. It gives the building a look of a weathered barn, which offers "curb appeal", (if there's any such thing at the end of a 1300 ft long road into a property)...??
We also built an addition onto this house which is a log house, and the reason that we built it is because we couldn't find anyone else who knew how. (Of course, we didn't know how either.) There really aren't that many reels where people show off building log houses other than little rustic huts and things, so - again - I had to resort to studying how the rest of it was built. I did talk to some people who worked for the defunct company that built this house, and got a few other questions answered. It's tough to build a log house - whether rustic or Lincoln-logish - as is this house, because there is no such thing as roughing in or framing. The entire build is basically "furniture/trim", in that everything shows. I had never put in a wood floor before either, but decided that likelihood of me doing as good a job as the best jobs I've ever seen was fairly high, because I'm ridiculously picky, and I sort of suspected that my pickiness would trump my complete lack of experience. The floor is beautiful, and there are no places where it creaks.
Anyone can do a really superb job on anything, as long as they understand that 100% is the minimum score allowable... but it's also important to define and embrace which things one can control and which things one cannot control.
I believe I saw where you put up a nice building for yourself as well..
MUSICAL INSTRUMENT REPAIRS:
There are more and more tools that seem to be available for sale claim to help with specific operations. I can look at a tool, imagine how it is supposed to be used, and just about immediately know whether or not it would help or simply be in the way, cost money, or maybe even offer an elevated risk for damage (LOL... though I suppose ALL tools offer an elevated risk for damage, don't they?)