To be a professional artist requires that you be consistently creative. It requires practice and nurturing of your artistic and expressive muscles.
And like muscles you must exercise them and not overdo it.
It's like a naturally filling well..
Your well of creativity will always be refilling but you can also dry it by taking to much from it. There is a right way and a wrong way to go about using it. These have been taken and morphed from Ernest Hemingway's Seven Tips.
Never fully empty the well by the end of the day; stop when there is still something there in the deep part of the well, and let it refill at night from the springs that fed it, so you always know what you will do next in your creative work.
Do not think about it when you are not working on it; if you never think about you art until you begin the next day your subconscious will be working on it all the time, refilling the well from the springs. But if you think about it consciously or worry about it you will kill it and your brain will be tired before you start - you will dry out the well and loose it's richness.
Consistently take from the well; finish consistently by have a regular routine of making creative work and expression, and maintain consistent vision by reflecting and reading your progress thus far every day. Consistency in practice and in style.
Start by using the richest water from it; to overcome creative block when starting, strip away everything and begin by thinking what is the truest thing you can think of. This is easy, there are so many true ideas you know or have heard, you never run out of things to say in a conversation and this is no different. If you start to elaborate too much you can cut the ornament and go right back to that true idea - everything else is chaff.