The problem is measurement. If your own labour is free, the profit statement is describing a business that does not exist, and every decision built on it inherits the error. Work that looks profitable may not be once somebody has to be paid to do it. Pricing that seems adequate may be below cost. You cannot find out while the largest input is uncosted.
Taking a regular draw, even a modest one, makes the real shape visible. It also imposes a useful discipline: a business that cannot pay its owner anything at all after several months is telling you something about the pricing or the demand, and the sooner that registers the more options remain.
The mechanics depend on your structure and are worth getting right early. A sole proprietorship or single member LLC takes owner draws rather than a salary, with tax paid through quarterly estimates on the profit regardless of what you withdrew. An S corporation requires reasonable compensation through payroll, which is a specific requirement rather than a preference. Getting this wrong is a common and avoidable problem, and one conversation with an accountant settles it.
Set the amount against what the business can sustain rather than what you need, and be honest that those are different numbers. If the gap is large, the answer is other income or reduced personal outgoings rather than a draw the business cannot support, because taking more than it produces converts a cash flow problem into a debt.
Then separate the tax as it arrives rather than intending to. A portion of every draw is owed, quarterly estimates catch people who spent it, and the failure is not miscalculation. It is spending money that was never yours in the first place.
Decide the amount on a schedule rather than taking what is left, because taking the residual means the draw fluctuates with whatever else happened that month and you never learn what the business actually supports. A fixed figure, reviewed quarterly, is easier to plan around personally and produces a cleaner picture of the business.
If the business genuinely cannot support anything for a period, treat that as a finding rather than as a normal condition. Several months of paying yourself nothing while the business appears to be working usually means the pricing is below cost, the volume is insufficient, or work is going unbilled. All three are addressable, and none of them get addressed while the shortfall is absorbed silently.