I didn't know what being a NED entailed when I took up my first plc directorship in the early 1990s. I'd been persuaded by the silky encouragement of Yve Newbold, a leading head-hunter and boardroom veteran herself.
I'd advised many boards, and the boardroom was where I had conducted much of my life as a lawyer - or rather, it often felt, in the corridor outside, waiting to give my 15-minute presentation, practising my air of professional cool and swatting into submission the butterflies in my stomach. It's usually at moments of corporate crisis that lawyers are involved in the boardroom, and it was my job to give calm advice in the face of serious threat. Hostile takeover bids, CEO dismissals or major frauds - I did them all.
But this was scant preparation for the real role of non-executive director, on the receiving end of advice. Having to decide with your colleagues how to act together in the best interests of the company is a lot harder than dispensing advice and moving on to the next case. What is meat and potatoes to a corporate lawyer is rare and unusual for most non-execs. The day-to-day business of the boardroom is more likely to involve budgets, strategy and sales targets than the high drama I'd been accustomed to.
But in today's uncertain economic climate, companies are going through tough times, and the stakes can be terrifyingly high. Just when the need for experience in the boardroom is greatest, head-hunters are reporting a dearth of qualified people prepared to become non-execs, especially in the financial services sector. The downturn has tipped the reputational risk/reward ratio into the unacceptable for many who previously saw the appointment to the board of a leading bank as a jewel in their portfolio.
Few senior people take on the role of non-exec for the financial rewards. The motivation more often arises out of a sense of wanting to put their expertise at the service of a business to which they feel they can make a contribution. But non-executive directors place their reputations on the line when they join a board and, nowadays, are increasingly reluctant to put at risk something they have spent a career building.
Choosing the right board to serve on can be tricky. It may be hard to resist the blandishments of head-hunters with a brief to fill and a fee to earn. And big is not necessarily beautiful - as the directors of Enron found. Things can go very wrong for non-execs, even in sectors where they have high-level experience - as some of those on the Northern Rock board discovered. In extreme circumstances, such as Equitable Life, directors can become embroiled in lengthy and stressful litigation. You can never do too much due diligence.
For women, I recommend seeking out a company that already has at least one other female in the boardroom. Not easy, as 24% of FTSE-100 companies have no women on their board. In my earlier days, I was often the sole representative of 'diversity', and it can be tough when you're expected to speak for the whole of womanhood.
I also often found that the observations I made were not considered until later on in a discussion, when one of the men would make a similar comment - a case of 'good suggestion, Denise... would one of the men care to make it'! Now that that I can make my points effectively and my male colleagues are used to having women on the board, this doesn't arise so often.
There's also, of course, the problem of queen bees. Relishing their unique status and discouraging the advancement of other women onto the board, they pull the ladder up behind them. But as Bill Clinton's secretary of state Madeleine Albright once said: 'There is a special place in hell for women who do not help other women.'
The boardroom can be an intimidating place at first - small things like where to sit or how and when to intervene can be awkward. On more traditional boards, the directors may have place-names and always sit in the same seat, moving up closer to the chairman as their seniority grows. New non-executives are expected to stay quiet at first, and questions are posed 'through you, Mr Chairman'.
Things tend to be less formal these days. Discussions can be lively and even fun. Some years ago, I sat on a board where the principal skill of a fellow director was to introduce humour at moments of high tension, and very effective it was too. At least one hot-tempered resignation was avoided thanks to him. I would not, however, recommend the court jester role unless you are very confident of your colleagues' sense of humour and have had a couple of successful tryouts in the Comedy Room.
The company secretary is your best guide to board etiquette. As a servant of the board but also an employee of the company, he or she has often served under a number of CEOs and chairmen and can be an important source of information and guidance. They know where the bodies are buried and, schooled in confidentiality and discretion, can help you avoid the worst faux pas. They also take the minutes, so if you want to ensure your points are recorded elegantly, become their friend.
The art of the constructive challenge is an important skill for the non-exec, but don't imagine yourself sharing stingingly insightful comments that will make everyone reel in astonishment. It's not your job and you're probably not being as insightful as you think, but if the chief executive does cry 'I never thought of that!' after one of your interventions, that's the time to really start worrying.
Baroness Kingsmill CBE has been a non-executive director of plc, private, charitable, arts and government boards. She is currently NED of British Airways.