Thought this may be of help to others.

First off a disclaimer of sorts. There are many different ways to pack and ship shrimp or other inverts/fish. Everyone has their own way. This is just my way and it works for me. I ship fish the same way for the most part.

I use USPS for shipping shrimp. It is the least costly. I use Priority mail shipping boxes. The boxes are free at the post office, you can ask for as many as you want. Alternatively you can use any sort of box you want, some people even use small styrofoam boxes, which work well. I can never find enough of them.

The cost for shipping is based on weight and how far the package is going. Typically costs anywhere from $5 to $8. The delivery confirmation is $0.75. If you have a scale at home to weigh the package, you can print a shipping label off the usps or paypal website, then delivery confirmation is free.

In some cases depending on how much you are shipping it may be more worthwhile to use a medium or large flat rate shipping boxes. The cost is going up on these sometime next year so not including prices on them. Look on the website for pricing.

No matter how well you package the shrimp, you need to look at the weather both where you are and where you are shipping to will be. Many times I have waited to ship or receive shrimp/fish when temperatures are a bit extreme. Know the temperatures that are safe for shipping. For red cherry shrimp I have shipped from the 50F to 80F range.