Cash flow is often called "the lifeblood of a business," and for several good reasons. But the flow of cash into most businesses is uneven and there can be times when a constrained cash flow creates serious problems, even if the long term situation is positive.
There are, however, ways to improve the cash flow of any small business and remove some of the worries about bills not being paid or not having enough on hand to pay wages. These mainly involve no more than adjustments to what you're already doing and so aren't difficult to implement.
Keep inventories as low as possible
Inventories are expensive in many ways. There's the interest paid on money borrowed to acquire items that are awaiting sale. There are also the costs for storage space and handling, as well as insurance expenses and the "opportunity cost" of what money spent on inventory could be earning elsewhere. In some cases, inventories are so badly managed that much of the material becomes obsolete before it can be sold.