Hats are not normally worn
There may be some regional variations, particularly due to local climate and season.
Jackets are not normally required for ladies. Although suits are increasingly popular.
A lady's business suit is an increasingly popular choice especially in senior roles.
Clean and well pressed. White is the universally preferred colour.
Must match the jacket.
At least knee length.
Preferably dark, grey, or beige in colour.
At least knee length.
Black, grey, navy, brown, or khakis are suitable colours.
The smarter the better.
Raincoat / Mac'
If weather requires.
More practical on public transport and popular in cities.
Should be a good quality analogue watch.
A small amount of jewelry may normally be worn but should not distract from your status as a professional business person.
Avoid religious symbols if possible.
There is more scope for jewelry in a creative role than there is in a more conservative environment.
A wedding or engagement ring is always allowed. Other rings should be kept to a minimum.
Different industries, cultures, and companies have their own conventions which you should try observe and adopt.
The purpose of full business dress is to present a uniform face which is conducive to business so it is generally counter productive to individualise your own style.
People generally like to do business with people like them themselves as they often feel they can communicate and work well with them.
Dress For Success
Generally it's best to 'fit in', so take your cue from your peers and try to dress to the same standard. This helps with interpersonal communication.
Or if you are ambitious and don't mind showing it, dress to the standard of the role that you aspire to.
Religious clothing or other items are generally allowed if they are prescribed by a recognised religion.
Optional items may not be appropriate if they may impact on those around you or restrict your activities.
Policy varies between organisations but in western cultures there is normally a right in law to wear clothing required by religious belief, except where this prevents you from fulfilling your duties (such as where it might conflict with Health and Safety considerations).