Mixing it Up

Many men refer to breaking up a suit as one of the cardinal sins of dressing. Wearing an orphaned suit jacket with odd trousers can look very bad when done incorrectly, but when done right can look quite nice. The suit's fabric is what makes the difference between right and wrong. Today we will focus on doing it right. Here, the same suit is used to make two different outfits.
When mixing it up, it is best to use fabrics in a plaid or a windowpane, as these patterns are ideal for sportcoats. I like windowpane, because the suit can be worn together in the office for an all-business look, but then one can ditch the tie and open the collar and head to a cocktail party. Splitting a windowpane suit up and wearing the jacket and trousers separately also lends itself to both dignified and casual looks. Here is my opinion on how to do it.
When wearing the trousers only, keep your upper half a little dressier. Wear a tie and a jacket, because the suit trousers are going to formalize the rest of your ensemble.
When wearing the jacket only, you have a little bit more lattitude to keep the rest of the outfit casual. Skip the tie, throw in a pocket square, and sport some trousers that do not combat the jacket. In both instances, the suit garment should be the only pattern; do not wear jackets and trousers with other patterns on them. You don't want to look like an optical illusion. A pattern in your shirt is ok, as long as it is different in scale (and hopefully different in type) than the pattern on your jacket or trousers.
I find that a striped shirt can look just fine (or even fantastic) with a windowpane jacket, but I would keep the shirt plain with windowpane trousers. The trousers have enough pattern on their own for the shirt to be competing with them. A subtle pattern in your tie is fine, however. Busy pants don't mean everything else has to be completely bland.
Try it out and let me know what you think!
Until next time,
Cheers!
-Paul