Summoning is a powerful, mystical device that is common fodder for midnight movies and schlock fests. It is often reserved for raising the dead, laying a curse, or engineering a demonic possession.
However, the mechanics behind summoning are actually very simple: Lens every ounce of your focus and power toward one thing. This is the very same mental tool used by Martial Artists to strike with bone crushing force, and to transmute pain into power, becoming a human laser and capacitor all in one.
You might ask "Wait, does that mean summoning is real?"
Yep. I believe it is. Even though it may not be exactly what we know and love from tales of ghouls & goblins, it actually works the same way.
In real life, it goes by many other names: creative visualization, manifestation, clear intention, single-mindedness, passion, obsession- they are all forms of summoning.
Finding your market as an artist doesn't have to mean selling out, or changing to accommodate the market. I believe your market can be whatever you want it to be, as long as you first define what that is. Fortunately, this necessary decision actually becomes easier, and far less monumental, when you make it based on what you love in your work and what you are trying to express with it. How do you know what it is you are saying through the macrocosm of your art? A good place to start is to look for the repeating themes, then dissect them to find the "why" within them.
This may sound idealistic to you. However, not only is it the mindset people use to hone skills, finish projects, change habits and better themselves, or how the rich get & stay rich, but it is the elementary answer to questions like: "How do I become the best Sci-Fi artist in the business?" Pour it all in. Draw nothing but subjects from your genre, tailor everything to it. [Caveat: Please learn your art fundamentals first, of course, then specialize.]
Once you focus every bit of your energy toward your goal, your goal will come toward you.
Again, to squash the idealistic tone of this into a practical box, this focus of your energy entails tangible things, such as; drawing every day (or as much as possible), studying your craft, gaining exposure,/marketing yourself, posting goal related art, and seeking out your community. That last one just might be the most important. You don't necessarily find work from within your community, but rather it will tend to find you. By this, I mean that once you embrace your community you put yourself in the path of your dreams, opening the door to serendipity and providence. It is the same as the saying: "if you want to be successful, surround yourself with successful people", and reflected in the Taoist saying "If you sit in one place long enough, the entire world will pass by your feet".
What is your "one place"?