One of the most important aspects about your invitations should be legibility. You want to make sure your guests can read the writing. Consider this when choosing a font in contrasts with colors and patterns. For instance, avoid light ink on light backgrounds and vice versa. Your text should pop off the paper when guests are reading. Be careful when choosing overly scripted typefaces. Word your invitations eloquently with listing whoever is hosting your wedding first. Traditionally, this would be the parents of the bride. Make sure to spell everything out, including the date and time of the event. You can even give your wedding invitations a traditional feel by adding a request line after the host's name.
In olden times the bride's parents paid for the wedding so the invitations would be issued by them, but now it could be the couple themselves or both sets of parents who are paying, so you'll need to agree between yourselves who is to issue the invitations.