Email gets more space than any other subject here, and the advice inside it is more specific than the headlines suggest. Always give people an obvious way to leave, because a list that traps subscribers ends up reported as spam and takes your domain down with it. Send something that reads as a newsletter rather than as a pitch.
Ido Meiron covers the other channels in the same measured voice: affiliate programmes, social platforms, internet promotion and running a business from home, each broken up by short boxed tips.
One practical instruction sits underneath several posts, which is to test everything on your own site before assuming a visitor will forgive it, since a page that irritates somebody for a few seconds loses them completely.
The writing never argues with itself and never tells you what failed.
Use it as a manual. Look up email if your list has gone quiet, and expect instruction rather than opinion.