Know your finances
It's really important to know your customer, your employees and your product. But, says Ella, it's also vital to know how the finances of your business work.
If someone else is in charge of the finances, make sure you always know exactly what is going on.
"You need to know your business intuitively and analytically," she says. "The best business ideas need to be grounded with sales and profitability. Cash flows can be tricky to master, but you need to know what makes your business tick."