Actually there are more than one type of patent.

There's utility patent, which is basically what you think patent is. And there's design patent, which is somewhat unpopular but got the attention when Apple sued Samsung for infringing its design patent.

These two types likely cover all your needs. If you want to protect the cosmetic features of your product, consider design patent. For all other cases, you'll be thinking a utility patent.

To add, if your design feature has a utility in it (i.e. when design serves a special function), then you will probably have to go with a utility patent.