Although I do very high quality work and get full points, my customers are very few. Is there a formula for me to change this situation?
No. Or everyone would be following it. Which would mean that even if a formula did appear, it would be played out in a month or so.
The method is to be Unique, offer something Compelling. Be the Right person (not the cheap person). Would you hire a $1 surgeon? Or would you look for one who cared about what they did and therefore about you?
This is completely at odds with the price it cheap and offer garbage approach common in these places and will seem to make it harder but that is because most of the buyers in these places are looking for $1 surgeons while expecting The Good Doctor magic and/or the right to sue and win big after (or at least to cancel the gig after they got the work). There is no win there.
Be different. Show how you do the special work (not just the same lame formula garbage). If you don’t have the technical skills, maybe you have another skill???