A gentleman always dresses for the occasion without overdressing.
There are some hard and fast rules, like bow ties for formal (white tie) and semi-formal (black tie) events. However, even then it may be appropriate wear a cassavas or even, in some cases, a black necktie. One must know the rules, know the setting (where the event is and what others are more likely to wear), and how the rules can be bent.
Flexibility
One way, for example, to dress down a suit is to match the sock and tie, rather than the socks and dress pants. This would allow one to still wear a suit in a less professional setting. Yet with dinner jackets, the opposite is true. One may match the socks to the dress pants to make the pants and jacket look a little sharper.
From there, it gets looser. Solid ties and solid shirts go well together. And pattern shirts matched to solid ties and solid shirts matched to patterned shirts works very well. Matching patterns to patterns can be difficult, but done right will make one truly stand out. Remembering to stick to three colors for the whole look will keep a gentleman looking sharp without overselling it.
Width
Tie width matters as well. Skinny ties (anything less than three inches) and fat ties (anything more than three and three-fourth inches) can look great. Yet, if one doesn’t want to stand out too much the average width of a tie should be around three and a half inches. When picking one’s knot, fat knots look odd on skinny ties. Things such as these should be considered as well. Be sure the knot size works well with the collar as well. If the knot allows one to see excess tie around the neck, a larger knot should be worn. If the knot is obscured too much by the collar, a smaller knot should be warn.
Style and Colors
Bow ties may be worn with any outfit, as with the same rules of deigns ans color. One must be confident in wearing them to pull one off well.
Lastly, dark colors look professional, yet one should not dress as if he is going to a funeral. A gentleman’s tie can make his attire pop is a very pleasant way. A nice charcoal suit is a dark as a gentleman should go. And, a nice red or blue tie can really help a man standout rather than fade into the shadows.
Final thoughts
A true gentleman will let the lady standout and outshine him. Yet he will be dressed and act in a manner that complements her completely.