Pocket Squares.

Check out these dude's pocket squares.
Don Draper from Mad Men wears a flat pocket fold.

While Prime Minister Winston Churchill opted for a puff pocket fold.

Any way you fold it, a pocket square always adds a needed touch of color and style to a suit or blazer.
Here is a How To for all sorts of folds.
And as I've said before you chicks should think about adding a pocket square.