The rule of thumb is that if you are attending a wedding and wanting to give a cheque you should make the cheque out to both the bride and groom used the married name unless you know that the bride will be keeping her maiden name.  As for the amount that you should give, well that all depends on how well you know the couple and what you are comfortable giving.  An aunt or uncle will give more to their niece or nephew then a college friend.

Giving money as a wedding gift is much more popular in many European countries then buying items from the couple’s bridal registry.  The amount that is traditionally given is the rough amount to cover the dish per person attending plus a gift for the bridal couple.  So if the dish was about $50.00 per person (the guest would never really now, just making a rough estimate) and the number of people attending were two, then the cheque would be for $150.00 ($50.00 per person to cover for food, plus a $50.00 gift).  Please keep in mind that this is different in every country, but normally the way one would think about the breakdown of the monetary gift.

You should never feel that you have to gift a monetary gift when attending an Italian or Portuguese weddings, where this type of gift givings is popular.  As a guest you should do what makes you most comfortable, both in heart and bank account.  At the end, the couple has invited you because you are a special friend or family member, not because of the gift they will be receiving from you.