There are quite a few advisers out there helping start-up companies – banks, accountants, small business agencies. Much of what they say is sensible. But few of these mentors have actually done it themselves. So I thought it was worth noting a handful of things entrepreneurs should not do when taking the plunge into self-employment.

● Do not leave your job. Develop your new project in the evenings and weekends until you are confident of success. Keep the salary coming in for as long as possible. If you need to go freelance, retain a contract with your old company. In the 1980s, while working full-time as a stockbroking analyst, I moonlighted as a partner in ventures as varied as nightclubs and a software business for a few years before joining the world of self-employment. These days, the rise of flexible working means this sort of arrangement is much more widespread.