Think about the shape and size of your invitations in comparison with the style of wedding you are having. Formal weddings typically use a rectangular card for a more traditional look. However, if your wedding more on the playful side, think about going circular, scalloped, or even a square wedding invitation. Keep in mind, the bigger the envelope the more costly the postage.
Choose invitations that actually look inviting. Thick, high quality paper with bright colors or a unique design that makes the envelope stand out from other mail that may arrive on the same day. Your invitations should excite interest even before they are opened, and if you have chosen your design well, they should evoke reminders of the happy couple as well!