E Marinella's rules:
"1. As in all the things, a tie is a matter of size: the correct one stays between 8.5 and 9.5 centimeters at the widest point.
2. It’s important not to tighten the knot too much, otherwise you’ll look “hung.” Also, always untie it in the evening and hang it up during the night.
3. Use the correct material: silk jacquard for regimentals; lighter silk model foulard for printed cloths; pattern for ties with an elegant tone; striped wool or Scottish patterns for winter sporting clothing.4. Have a tie for every occasion. In the morning, choose a lightly coloured, patterned tie. In the evening, opt for a darker one.
Don't like this one.
5. Don’t take advice and don’t remit your tie choice to anyone. The only rule is to follow your instinct. Choosing the tie has to be an irrational act.
6. At the same time, your instinct has to follow a certain logic too. Absolutely avoid ties that are too wide and have showy or centralized patterns. Also avoid ties that are too pale and anonymous. Remember that the tie reveals your personality.
7. Choose ties in definite colours, have small patterns (pois, lozenges, little squares, rhombus, small cashmere prints), or stripes with two or three colours at the most.
8. The colours of a tie must stand out against the suit and shirt, but not clash. It must also be darker than the shirt and more intense than the jacket. With serious clothing, a tie is often the only place for color, but don’t go to far with this! Avoid pea green, canary yellow, fire red, and sugared almond pink. Choose darker colours (but not anonymous ones) such bordeaux, dark blue, hunter green, and dark brown.
9. Coordinating your tie with your shirt a mine-field where only good taste can guide you. Some basic tips, however: avoid pairing a thick patterned tie with a checkered shirt, or combining a regimental tie with a striped shirt and striped jacket.
10. Never coordinate your tie and pocket square. It is a useless, anachronistic affectation. Always avoid having a too cared and affected comprehensive look; opt for relaxed elegance."