Jackets of tweed or another fabric can be a part of two-piece outfit or specific item. If a model has sport cut, and you are not going to spend a day in the office or to go to the business meeting or conference, it is not obligatory to obey courtesy rules: to wear, for example, a T-shirt or polo-neck shirt and shuffle on blazer.
A different story is, when tweed jackets are a part of formal clothes. Then there is no room for familiarities. If some slips or deviations from the unspoken rules of decorum are noticed in your suit, nobody will make a comment on it, but the image of businessman will suffer a little.
If you go to work
If you go to work, remember, that formal jacket is worn with a tie. The tie can be coloured or sole-coloured, but it must match with the colour of suit or shirt and the width of lapels. Ideally, a tie should be lighter than jacket and a little bit darker than shirt.
One should not forget that a shirt with long sleeves is worn under every jacket. It is a sign of good manners if cuffs of the shirt are seen under the jacket’s sleeves (but not more than 2 cm). Dark clothes are proper for work and light jackets are pertinent for holidays and informal meetings.
In the office ties with vivid or gaudy pattern are inappropriate even if they match with the suit well.
You can learn more about different elements of jacket and about elbow pad jackets to create a harmonious and whole classic image.
How buttons are being fastened
If you have already bought a tweed suit, pay attention to the amount of buttons on your jacket. Generally, there are two or three of them but on the double-breasted items it can be six buttons. If you work in the private office, you can unfasten buttons for convenience. It is acceptable.
When you are at the official reception (at prize distribution or you meet a personage etc), all the buttons must be fastened. In other occasions the bottom button is left undone and two upper buttons are fastened (it is allowed to fasten only the upper button). Exception is models with one button: it should be always fastened.
How to wear accessories
A man who keeps rules of decorum has always two handkerchiefs. One is in the inner pocket of a jacket and another is in the chest pocket (it is believed to be a design element). Bowties are a supplement to dark suits and are worn on the most special occasions.
A tie of silk (natural or acetate) is chosen to the evening jacket. A shirt with usual casual cuff links is worn as clothes with buttons. There are no any special rules except that accessories should match with suit, tie and the shirt itself in colour.
On feasts (presentations, exhibitions and other important events) shirts with adornment cuff links are worn under stylish jackets with unfastening buttons on sleeves. It is allowed to have a bottom button of the jacket’s sleeve unfastened, if owner of the expensive accessories wish to capture the attention of the public.