If you haven't tried it before, wearing a tie with a shirt in rich plaid can be a tricky task. Start simple by pairing it with a solid knit tie, in cotton or wool, in a color that works well with every color in the shirt's plaid.
Such combinations are more than a little bold, but don't be afraid. And expect to fail...a lot. For as often as I've pulled this kind of thing off I've left the house looking a bit foolish. But as with anything, practice makes perfect. The more you attempt it, the better of an eye you'll get for it.