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.
If you want the look of a traditional wedding invitation, but would like to implement your wedding colors, consider using one of your colors as the lining color for the envelopes. This is a subtle and attractive way to customize the appearance of your invitations. Other places to add accent colors are on envelope seals, monograms and motifs. Careful use of color can add drama or whimsy to your invitations without adding much to the price.