Sometimes it's almost impossible for me to find a proper greeting card for special occasions. A solution for this task comes from Hallmark Card Studio, a Mac program that lets you create and print personalized cards, calendars, invitations, and much more.
This application gives you access to a wide variety of card templates and clipart samples to choose from. In addition, you can include your own message in any text style you like and attach personal photos or geometrical shapes to your e-card with ease.
After you finish polishing your greeting card, you can save it to various output formats, print it directly from the program's interface or send the resulted e-card via e-mail to friends or family members.
A disadvantage of working with Hallmark Card Studio is that it occasionally runs slow and the fact that you can import pictures only from iPhoto and iSight cameras (unable to select photos from local drive).
As for the rest, this program provides you with all the tools and clipart you need to create your own greeting cards. Its price is affordable and the results are high quality.