For my cuttings i just did a usps flat rate padded envelope. I put the cuttings inside some cardboard (for protecc) and slid them into a gallon zip and then into the envelope. I'd imagine a flat rate box should be super simple.

For onsie/twosie orders a padded envelope would prob work just fine. Maybe do like i did with some extra cardboard 🤷‍♀️

Second this

I just use Pirate Ship

Third

Use PirateShip.com for your shipping. It will give you the cheapest rates and allow you to pick which carrier. Also gives you estimates. Use padded if possible, boxes of you must like if it’s too big for padded or if you’re shipping glass. Use recycled news paper for packing material. Thanks @JackTheMimic for the tag