I posted some of these picture last year at this time but here they are again! I hope they are helpful for any new swappers.
1. A picture of the stamps. The 2-ounce "forever" ones I buy have flowers on them. 2. A picture of the envelopes (I use A9 but I've seen people use regular business envelopes too). You can see the candies stacked in 6 rows of 8 (48) plus a couple extra on top. I throw a few extra in because I'm worried I might miscount, or one of the candies will be cut incorrectly, etc. 3. My stack of envelopes with a book on top where they sit flattening all year waiting for the time to mail.
I also put these directly in the mailbox outside the post office. I've weighed them on my kitchen scale at home so I know they're under 2 ounces. I don't want to take them to the postal counter then have some random postal worker get into an argument with me about weight, dimensions of envelope, too thick etc. Just dump in the mailbox and so far they've always come through just fine.