How about this.
What seems appropriate, facilitates trust and conveys authority? These are the key factors when determining what's right for your business.
Sometimes subtle, what not to wear on an evening out can be a tough decision. Slightly overdressed for an occasion can be disasterous for your social life!
In business being overdressed can be just as bad as being underdressed. 'He's trying too hard.' or 'This guy is a salesman.' may be the thoughts of a potential customer.
A tradesman is expected to be dressed appropriately and with it comes confidence and trust which is essential at first contact. If there is incongruency between expectation and presentation, the job of closing a deal is much harder.
Around 80% of communication is non-verbal, let it work for you rather than against. Why do Doctors wear white coats and policeman wear dark uniforms? In a word, authority. Society in pre-programmed to respond in certain ways to symbols of authority 'within a certain field'. That's why the 'Scientist' in the new improved Daz advert wears a white coat, because with little or no evidence to the contrary we look to authority figures in that sphere to make the decisions for us.
Clothes also communicate attitude and paradoxically can work for you if the mismatch between expectation and presentation is through the floor.
If in your profession you are expected to turn up in a smart, short sleeve shirt and trousers, but arrive in an old T shirt, cut off jeans and trainers, this can be taken two ways. Either you are a cowboy, or you are so succesful you don't need the business and don't give a damn. This approach can be very powerful if coupled with an initial referral because the trust evaluation is already assumed.
In this instance you are creating a posture of authority and scarcity. I don't need you, you need me. Now let me see, I might have a slot in January for you, you jump through MY hoops.
I do not recommend this approach to beginners as you may well lose business rather than secure it.
All in all, every profession, business, culture need to develop it's own presenting image. The place to start is thinking about your customers and their expectations.'