This is a business topic.
I've discussed in various journal entries in the past about the division between the administrative side of business and the technical side.
Any artistic endeavor requires a working knowledge of both. This of course applies not just to photography, but also musicians, painters yet extends to any field where there is a technical side and administrative side.
Sticking to photography, and based on my personal experiences I will share what I have observed to be a workable formula for growth and viability in regards to how much of your time is being spent on what aspect of your business.
It is very obvious that you must technically be good at your craft, of which there are plenty of ways to achieve this, the most important being, to do it over and over, gaining experience while studying any theoretical side. The experience part is one thing no course can teach you. Everytime you increase familiarity, encounter and overcome new problems or circumstances, you add to your reservoir of service potential. This is worth something to people.
Where most artists fall down is on the administrative side. It's been said a different side of the brain is working. This may be true. That aside, being a great administrator and communicator is key.
This pie chart is roughly what I've found works for me. It may look different to your business model. It's meant to be informative not absolute. See the last graphic at the bottom to gain insight into what encompasses "business administration".
With this formula I am a service provider (and sometimes therapist) that happens to make imagery. For me in particular, I enjoy finding out what people need and want for imagery and then ensuring that it will really drive their brand home to their target market. Or if I am shooting women, it's to embellish their unique qualities and to record their beauty.
Artists that may be great but tend to fail (in business), have a chart similar to this:
People who go into business with the above as a skillset and/or devotion of their time, usually don't make it in business. They don't bill right resulting in insolvency or pissed off customers, they don't communicate leaving customers in the dark about what's happening, they don't follow up. They don't stay in touch. They don't have ample devotion to promoting themselves, marketing, PR, they don't pay taxes or have a legitimate business leaving them open to attack by government, or people can't find them. All of these things lead to little or no confidence by a potential customer in your ability to deliver. Will the customer get what they pay for? Will it be what they want? On the other side, part of business administration is knowing what to do with your money once you have it that will help ensure repeat and future business, viability and a lifestyle that includes not having to eat Top Ramen. Some think, ahh now I can afford another lens. That's not exactly how a business operates. By the way, I purchased my lenses in the order that I calculated would give me the greatest return for my money. In other words, which lens will pay for itself and make you more money, not what's cool to have.
You can trace down problems you may be having to the green and yellow fields being absent or your blue field (technical) being sub par. It's one of those three areas where you will need education and/or practice.
So how much time should you spend on these other areas of your business outside of the actual creative stuff? The answer is, enough time to where you see an increase in your income toward and attaining viability (that includes not living as a pauper). When you hit the right ratio, it's like magic. The thing to remember is that each business model will have a different ratio and don't be afraid to adjust it as your company grows.
I recommend a business mentor to assist you in deciphering and monitoring things, someone very skilled in business with an appreciation for art. It really does help to have other perspectives. To your success!