I think it's impossible to say, really!
Probably there are 'fixed' and 'intangible' factors. So fixed are things like age, looks, location. I'm a middle-aged BBW so I never expected to be turning them away in droves. Intangible would be things like services offered, customer retainment, marketing and so on.
My advice to anyone starting would be to take a thorough look at e.g. AdultWork and price yourself according to your peers with slight variations. So, say you're a 25-year-old size 12 busty blonde who works from an average home and doesn't do CIM and anal; if there's another size 12 busty blonde 25-year-old in your town who works from a luxury apartment and does CIM and anal for 150 an hour, maybe you would charge 130. I think you need to brutally honest with yourself and realistic about your prices. It's all very well feeling you're 'worth' 200 an hour, but if you get no bookings, you won't eat!
Then there's customer services. I'd say if fewer than about 30 percent of your clients ever return, you need to ask yourself why. Are you warm and welcoming? Do you watch the clock? Do you limit the amount of pops or how vigorous the sex is? Are you offering services you don't really enjoy, and it's showing? Do you offer time to shower, decent toiletries, clean towels etc. Do you offer a drink? Do you have a decent range of different condoms? All these things can make a difference.
And marketing - do you market just on AW, or do you also have your own website, Twitter account, maybe Instagram, listings on other profiles? Do you engage on any fora? Is your profile brief and clear? Do you return messages fairly promptly? Display your phone number? Is your availability well explained and your booking procedure clarified?
If you can't work from home, are you touring in the right areas? Picking the best hotels/apartments for discretion and client access?
In summary, I think you need to experiment, and if one or more factors aren't working, change them. So e.g. if you hate doing OWO, change to OW and market yourself as being health-conscious. If there's one day of the week that's always dead, perhaps do a discount on that day only. And think about how you interact with clients, both at the booking stage and face-to-face.