Designing a symbol is like alchemy. One carefully gathers all the ingredients, places them in the creative department of the brain and gently stirs while they are reduced to their essence.
Standing by with a pencil, it is then it's a matter of capturing the first 'flash' and getting to work polishing and shaping until the symbol takes form. Dozens of variations may spring from the original inspiration as all the requirements are taken into account.
Then it's a matter of testing with mock-ups of posters, letterheads, bottles, clothing, stamps, billboards and so on. When everyone is happy with the result, the symbol is released into the wild.
Enlarged, the examples on the right have accompanying information about their application.