Angie and I have talked and taught about this but this is key ( along with the intention of developing speed )..
you have to know what you want to produce, produce it regularly, and then study what makes it more profitable for you.
Someone got mad at me not very recently for suggesting there is only profit in things you produce repetitively, but let me clarify how like this selection needs to be.
you don't have to use the same method or the same fabric or the same anything you choose not to. But your core choices need to be the same as if you were applying limits to an employee.
Angie does this well because she breaks it down for herself as if she needed to explain it to three year olds. If it's not a good habit that supports production better than any other habit, then that needs to change.
The thing that finally convinces most people ( I am guessing ) is when they do have more work than they can handle, and then get sick of the hours. Then, you get down to it and streamline.
Until you have that volume, the incentive is too abstract.
In short, profit lies in speed, I'd love to get $40 for a cushion, but fact is, if the pile is big enough, I can make a profit at $8. That's where you want to aim. If you can't train yourself to be a sewer, you are never going to get to where you can roll with the punches when the work available isn't ideal.
An example of my systems is the picture trail series I did with the red/yellow sofa fabric. I used patterns drafted from measurements, and then stack sawed them.
In the beginning your systems have to use what you know at the moment. When I first started my systems were simple, I used what I knew, and treated myself like an hourly employee. I didn't answer the phone, I sewed regular hours, I set a goal, and timed myself, and took note of wasted movements, reviewed at days end and changed my systems regularly when needed.