Quick story I spent 38 years from right out of high school working on electro-mechanical aircraft instrumentation, for the first 25 at Sperry Gyroscope and then 13 at a mid size airline in the instrument shop. So I'm like fresh out of high school and had worked on dismantling gyros and a few other things the summer before. Along with high school electronics that was all I had. A lot of the instruments were very fine mechanical engineering. A lot of instruments also used hairsprings, so there was a lot techs with a watch makers background. They all had the machinist type tool boxes. One senior tech in particular I got to know let me try his watchmaker quality tweezers and jewelers screw drivers and impressed on me as a 19yo on the importance of quality tools. So I followed his advice and took a bus downtown to Geneva Watch. This would be '75, so I bought 3 different Swiss made Dumont & Sons fine tweezers, back then they were like $25+ each. I also bought a set of Moody screwdrivers, over all it was all over a Cnote. Absolutely the best move I ever made, almost 50 years later those tweezers and two of the drivers spend their time on my on my desk and get used often enough still. With a little touch of a fine stone I bet I could pick up a .002 shim. So I learned a long time that you'll never regret buying quality tools, it's never cheaper to have to replace them. Same as buying the Knipex cutters, if that's the best tool needed then just buy it once and you'll be good forever.
At Sperry it was union so when you were given something you had never worked on before you would get so much training time and help from a lead hand to train you. Some of these instruments were quite complicated with R&O times up to 100+ hours, think of all those cockpit instruments like the larger indicators and then of course all the different gyroscopes. At First air it was different, you could end up working on anything off the plane, if it had a wire anywhere it came to our shop. It was actually rare for me to work on anything I'd done before so everything was new. In the shop basically when you pick something to work on off the shelves the first thing you do is go grab the manual and start learning. Or we could go into the hanger and work on a component on the plane itself. I remember one week I spent on a new plane they had bought and I had to modify all those overhead personal service panels. I also worked on clock movements and replaced hairsprings to repair/modify/certify these clocks for use with lithium battery in cold climates up north, and the next day I could be working on an engine harness, or ovens, or coffee makers. I learned a lot. Never got bored.
So with all that being said hehe, this is what I have learned over time. You learn some when explaned how to fix or do something. You learn more from reading a good repair manual. You then learn some more when you watch how it's done. But you always learn the most from doing it yourself and then the more you repeat it, the better, faster and more confident you get at it. Whether it's working on a vehicle, using a chain saw, adjusting a carb or dismantling and maintaining your reels. Things get easier to do.
Cheers