I mentioned before I was going to include where to find some fun and interesting stamps. There are many options as you search online. It is really amazing at all the options available. I love that you can also get postage that matches the invitations. It is also fun to get old stamps that tie in the colors. Here are some great places, and my favorite, go-to postage options:
USPS.com They often have past years Love stamps available
ETSY One of my favorite stops for everything parties
Ebay
Minted They have postage to match the invitations-this option is no longer available. The Post Office nixed the โdesign-your-ownโ option
Zazzle You can design your own postage-not available at the moment
Make sure you know how much postage you will need before ordering anything. You can get one stamp with the full amount or have fun with multiple stamps. You can get creative with how you place them on the front of the envelope, as long as they are in the upper right corner.