The silver tie clip and the gold one are your two main options. Like always, choose the color that goes best with your skin and the color of the shirt and suit.
Gold goes best with darker complexions and silver goes better with light complexions.
Also remember to match the color of your belt head, watch, and cufflinks to your neck piece.
When buying new items for your wardrobe keep in mind that these are low on the priority list.
The popularity of this neck wear fastener has dramatically declined over the last few years and will probably die out completely in the near future.
A major reason for this is because they can appear flashy at times and really aren't all that useful in non-windy conditions.
How To Wear
You'll find that many people opt to tilt these items down at an angle. Some say that you must wear them at a 45 degree angle and others say that they should be kept horizontally.
Put it on and look in the mirror. Whichever you think looks better is the best way for you to wear it.
When To Wear
This might want to be one of those items that you only wear while cold calling on a windy day or maybe while walking through your down town area. Some people only slip these on temporarily while they eat.
This isn't an essential item by far, but it isn't something that can hurt you either. If you'd like to wear a tie clip, go ahead. If you don't want to wear one, thats OK too.