As someone who constantly strives to improve my writing and promotion skills, I've read plenty of how-to books and articles over the past 35 years. I’ve also soaked up information at numerous conferences, workshops, seminars, and critique groups. I’m going to share some of the advice that resonates with me. Maybe they will for you too.
First, stop competing with other writers. There will always be more talented or prolific, better connected, and luckier authors than you. Plenty of them will earn more money than you do, but none of this is important because their careers have nothing to do with yours. What really matters is your journey, that you make the most of your skills and opportunities.
Second, don't spend huge amounts of time worrying about failing. If you're inclined to fret, then worry about not trying hard enough or coming up with ways to work more efficiently and create publishable work. Rejection, lousy reviews, and poor sales months (even years) will happen. Most of those things are out of your control, so focus on what you can control.
There is no clear definition of what constitutes a successful author, so don’t let someone else do it for you. It’s a personal thing. A writer’s goals and ideas about success vary widely. It could be the number of books or short stories written, the number of contests won, number of books published, workshops given, great reviews, and income. Figure out your own definition.
Learn to work at a pace that suits your time, energy, and other responsibilities. Please don't fall into the "I must write multiple books a year to stay on top of Amazon's algorithm" trap. For the great majority of writers, it's unrealistic. If you're going to invest time to write a book, then invest more time to see that it’s edited properly. Great writing isn't a scribbling race, it’s a learning process.
I've heard more than one writer state that he/she is counting on writing income for their retirement. This is the world's worst retirement plan. Sure, we've all heard the stories about unknown writers rocketing to fame and fortune, but these incidents are still rare. You can hope for writing income to supplement your retirement plan, but to count on it is incredibly risky. You've probably heard this many times before, but write because you love it, not for the money.
Lastly, publishing your novels can put you in the poor house. I’ve met many authors who've decided to go all out to promote their first book(s) by flying to conferences to take part in panel discussions, give workshops, and do book signings. Based on my experience and those of colleagues, it never pays for itself financially. In fact, you're lucky if your bar tab will be covered. You will enlarge your network and potentially gain more readers, but this will likely mean that you’re operating at a loss for at least several years, if not longer. Be prudent with your promotion spending and keep in mind that the big publishers aren’t likely to give you a promotion budget. In today’s world, there are plenty of free and low-cost marketing venues to promote yourself online.
Above all, follow your instincts. There will be conflicting advice from books, writing colleagues, agents, editors, critique groups, and well-meaning friends and family. At the end of the day, do what works for you and, above all, enjoy the journey. It’s your life, your words, and they should mean everything to you.