André,
Most consultants don't "wait for calls" in the early stages. They market and sell their services, like any other business. If they are skilled and fortunate enough to develop a large and repeat client base, it is possible that some customers will seek them out directly.

Some top national experts in large multinationals will have developed a solid network of people who have, over time, learned to know and trust them. Consequently if they choose to set up their own business their network contacts will naturally think of them. As an example, I have been retired for about a year and still receive one or two calls each month from my network of comp & ben directors of large French multinationals (I live in France) asking if I could take on assignments or help them. Incidentally, I don't take on assignments but am happy to discuss ussues and give a view if it helps them - or suggest someone else. I hope this undrelines the importance of being not only technically competent, but also the need develep and maintain a useful network that trusts you and has confidence in you.

Once again this is not an either/or situation but one of both x and y.

Isn’t there some sort of ratio around 30% of time is marketing, networking and proposing. 40% of time is working and 30% of time is preparation / down time.

Agree entirely with Ray - consultancy is not a case of “build it and they will come” but a long and consistent struggle to establish your brand, offer and reputation. Your other post around FTCs is probably a better way to go to gain experience unless you are very comfortable in marketing and networking yourself.

Generally yes people do hire interims and consultants who have been there and done that rather than learning on the job. .