I get lots of ideas, Phil: most of them, but not all, upon a subsequent 're-think', turn out to be non-starters. The really important thing is to detect the imposters before serious resources are deployed - and that may require 'input' from others, for which this very forum is an invaluable resource.
In addition to that - and not necessarily related to radio & electronics - I have two mottos:
1. "Your first idea is never the best one. Let it tick over in your mind for a day or so and a better one will emerge". Similar process to solving crosswords, etc.
2. Before 'diving in', get pencil, paper, eraser and a ruler: make a drawing; do the arithmetic. Particularly relevant to woodwork tasks. "Make your mistakes on paper: paper is cheap; other materials aren't."
Al.