As a sole trader, your finances can be complicated but are vital to both your personal life and your professional career. Self-employed workers, like yourself, often struggle with making a consistent income and completing the annual tax assessment.
It’s really important for freelancers to do a great job managing their money so their families and businesses never go without anything they need. 
#1 - Check into Public Liability Insurance 
Are you paying the best possible price for your business insurance, including public liability insurance? Or are you just going without public liability insurance since you’re worried the cost will be too much?
Start your money management plan by evaluating your business insurance portfolio, particularly public liability insurance.
Source: https://www.entrepreneurshipsecret.com/money-management-tips-for-self-employed-workers/