The combination between sweater and tie is very old, but never stopped giving your enormous contribution both to more formal as informal visuals.
In addition to classical, it increases social clothing and mounts at the same time give liberty to casual choices. Here are some tips from extrareference.com in how to wear the sweater with the tie.
Prefer Plain Sweater
The best option is to have a plain sweater, because then you can vary more the choices in a white shirt and tie–always following recommendations of these style pieces. When the sweater has details, you end up limiting the combinations and will have to resort to often standard white shirt and/or black tie.
Sweater With Suit
With the use of the suit, the more sober and neutral the sweater, the better. Bet on colors like black, gray and Navy Blue and always use flat pieces. If possible, choose a sweater that has the same color (or similar to) the suit.
The Social Visual
When using sweater and tie for more formal occasions or work environments in which social clothing is indispensable, remember to use the shirt into the pants and wear shirts and ties more classics. The color of the sweater must also be discreet, more neutral.
In Visual Casual
If in your work there is freedom to choose the clothes and for more informal occasions, the shirt can be loose (out of pants) and the range of options for shirts and ties is greater–remembering, of course, care to combine the two pieces. In regards to color, the sweater can also run some of the basics.
Tie Out: No!
It may seem an absurd recommendation, but it never hurts to reinforce: do not use the tie out of the sweater under any circumstances.
Evenif it is not very common, you can use the sweater with bow tie. But this combination serves only to Visual and informal occasions. So you gain freedom in the choice of the sweater and the details of both the own piece as in shirts and ties.