Good question
To be serious for once it is a bit like any form of thinking/exercise the more you do it the easier it becomes
I started building things when I was about 8yrs old (my first crossbow that was popular with my parents) and just kept going
I've had some good ones and a lot more total disasters (the exploding roller shutter door at work springs to mind) I've set fire to myself more times than I can remember and sawn sliced and chopped lots of bits off (casualty greet me by name now)
The one important thing to get if your going to invent things is an understanding, quick thinking, good tempered and undemanding WIFE "believe me" she can drive you to the hospital after you've blead all over her new carpet (without complaining)
So after 40 years of practice and near death experiences I'm starting to get quite good at it
Next a book about how I have survived