It's basically the Alfreddson protocol for Achilles, only you do it barefoot and you add a small rolled towel under the toes to get a better stretch. Here is a basic picture. You don't need the backpack. You start with 3 sets of 8 daily and increase up to 3 sets of 15. Add this to some basic stretches.
In addition to this program, heel pads work for some, as do arch supports (I like Super Feet), night splints or the more comfortable Strassburg sock, rolling a frozen can/water bottle along the arch, and making sure that every pair of shoes you wear is providing some type of support. Most people don't need expensive custom orthotics. Shoes are often the culprit. Don't walk around barefoot in your house or in crappy flip flops.