Although entrepreneurs are non-conformist individuals, we must still face the fact that we are judged by our appearances.

In particular, how we dress sends out a message about us to those with whom we want to do business.

So it is perhaps not surprising that one of many products that are actually doing well in the recession is the white business shirt.

Where coloured shirts may project dynamism and originality, the plain white suggests reliability – a commodity that is valued more in the current climate.

This is a point not lost on the white shirted trend-setter Barack Obama, who realised long ago that a radical politician should make a special effort to dress conservatively. This may also explain why the white shirt is more popular in Europe than in the USA, where some business circles are more sceptical about their President.

Either way, here are some dress rules that an entrepreneur breaks at his peril*.

1   While it is possible to get away with all manner of casual dress in many sectors, every entrepreneur should have at least one proper business suit in his wardrobe, and should wear it whenever the occasion demands.

2   If uncertain whether a particular occasion demands the wearing of said business suit, wear it – better overdressed than underdressed.

3   It is also practically compulsory to wear a bow tie and dinner jacket for formal occasions. Those who sport brash tuxedos, or who wear a lounge suit to formal occasions out of misplaced egalitarianism, always make fools of themselves. But such occasions are increasingly rare, so hire may be a better option than purchase. But, if hiring, go a a classic look and make sure it fits well – otherwise you will stand out as a man in a hired suit.

4   Sports jackets at work have come to be associated with the lowest type of salesman, and so are best avoided now.

5   It is also best to avoid a shirt with a breast pocket or short sleeved shirt when wearing any sort of jacket. It implies someone from the shop floor has been told to dress up for an occasion above his usual level.

6   Discreet tattoos are acceptable in some sectors – construction, mechanical engineering, rock music, etc – but nothing destroys business credibility as quickly as any form of facial piercing.

7   Jewellery on a man does not inspire confidence: a wedding ring might suggest a degree of stability, and a signet ring with a family crest implies heritage. But any more than that invites suspicion, and a functional watch is more reassuring than an expensive Rolex. Gold chains are strictly for drug dealers.

8   Tie fashions vary, but a tie that is too short to reach to the belt, or too narrow to cover the shirt buttons, always looks ridiculous.

9   Those of us who are not as thin as we might be – a substantial proportion of the population of the West – should admit the fact, and not imagine that we can get away with fashionable clothes designed for people with the build of a drainpipe.

* NB: When we say “his” we normally mean “his or her”, but in this case we really do mean “his”; women have their own rules, which are far more complicated, and on which no man would be wise to comment – Your Contributors.