In August 2007 it was reported on this website that there is no such thing as a coat of arms for a specific surname. A coat of arms belongs to an individual and only his/her direct descendents may use it -- with certain provisions. A person in South Africa who wishes to use a coat of arms legally should register it at the Bureau of Heraldry.
On the website Creative Genealogy there are a number of articles about the design and use of coats of arms. (Click on the blue to view them.)
A few extracts from these articles are:
Design Considerations: The number one rule in creating a coat of arms is, Don't Overdo. Don't put in too many colors, don't put in too many symbols, don't make it too elaborate. When it comes to a coat of arms, simple images work the best in most cases. The thing you want to keep in mind is, how/where are you going to use your coat of arms?
Printing: There are lots of ways to use your coat of arms in print. From greeting cards to stationary, stickers to book covers ... the ideas are all here for the taking.
Display: Display your coat of arms with pride. You might be surprised at the options you have available to you. If you'd like to adorn your home with your coat of arms you might consider having it laser etched into a wood, glass, stone, metal or leather surface. You could even have it etched into your shower door.
Wearing it: Once you've designed your coat of arms it's time to show it off. One of the most fun ways to do that is to wear it.
Using Clipart: It's time to get down to the business of creating a coat of arms. There are a number of ways you can go about doing this. If you're a talented artist, you can sketch one freehand, then scan it into your computer. If you're a skilled illustrator you can create a coat of arms using an illustration program.