1.  Photos can be used - but it is the text that should stand out!  After all, you want to make sure that all of your guests are able to clearly see and read each word of this important (and exciting) information.

2. Same goes for colors - keep them limited!  You don't want something that looks too busy - You do want something that will wow your guests when they open your envelope.

3. So many fonts, so little space!  Chances are the text is going to be very small (usually 10 or 12 point) and you may not want a font that becomes more difficult to read as the size is reduced.  You do want a font that expresses the theme of your wedding day.