When you are notified that gifts are ready in your account you can log in and access these gifts from the “My Gift Campaigns” tab. You’ll see an “Edit” button next to each gift. Click the button to personalize the message that goes out to your contacts.

Don't see Draft Gifts under "My Gift Campaigns?" This likely means that the newest gifts aren't quite ready yet. You'll receive a notification when gifts are ready in your account and you can edit them at that time.