The toughest part for me about being "handy" is that generally if I haven't done a million times - I just plain suck at it. I dread the day when I help my son craft some project, and it's all wobbly and has open seams and - well basically sucks at it. My Dad was an outstanding craftsman - several pieces of furniture in my house TODAY are things he built - and I even helped him BUILD IT. I just don't have the eye for it.
SOME things, you just learn from experience - I have learned for instance, when something needs to be bolted or screwed together, you don't tighten the first one all the way. You learn - don't OVER tighten, lest you strip something. Learn from experts - I learned from a carpenter I worked for, for many years to hammer by a technique that resembles throwing, where your arm largely guides the hammer and you use your whole arm and body. HE could pound 16 penny galvanized nails into pressure treated wood all the way with one hit - and could do it at a rate of about one every second or two (nailing a deck, for example).
Once he tasked me with making stringers for a small deck - and it was a disaster. I knew HOW to do it - I just had no skill for it. He could look at a full stair and say "that's a quarter inch out of level". I can't do that WITH tools. Even though he was my best friend, I finally quit and told him, I was simply a liablility and his business would do better with a more skilled laborer.
Every home I've lived in has at least one example where Sam really shouldn't have done anything - and possibly ONE where I actually did it right. It's just too expensive nowadays to get it wrong.