Gift-giving etiquette varies by occasion and even depends on where you live! Here are a couple of tips to help you sort out when you should and don't need to bear a gift.
Generally, after you receive an announcement for a couple's engagement, sending a gift is not required. The exception is if you're invited to a party in the Southern part of the county, then the answer is "yes!" Remember, you can always send a gift to the newly engaged couple's home and it needn't be extravagant.
As for gifts when it comes to announcements for weddings, graduations and retirements, no gift is required — though cards are always welcome and a nice gesture to congratulate someone on their good news.
And if you are a house guest, a gift is customary but you needn't show up with a gift in hand; It can be sent to the host's home later.