Step 1. 

Prepare the fish. Keep the fish in a separate tank with the right temperature and clean water. Check for any signs of disease, as you don't want to sell your customers sick fish

Step 2.

Be prepared to pay for overnight shipping. When shipping fish, it is best to ship overnight. This is usually more expensive, but the fish has the best chance of survival this way

Step 3. 

Put the fish in a bag, then fill the bag with water. Fill the remaining bag with fresh air or oxygen. Three or four packs of fish (put the bags together).

Step 4.

Put the fish in the box. Put the bagged fish in a Styrofoam box. This will help isolate the water inside and maintain the proper temperature. Line the inside of the Styrofoam box with newspaper so the bag doesn't wobble too much. Use newspaper wrapped hot/cold packs depending on the weather and type of fish. For example, if it's tropical fish, heat the pack in the box. Seal the styrofoam box and put it in the cardboard box. Sealed carton.

Step 5.

Contact the buyer and make sure they are ready to receive the fish when they get there. Consider airfreighting the fish via a reputable airline. There are several companies that specialize in shipping what they call "live tropical fish." Label the outside of the box, such as "Fragile" or "Live Fish"

Step 6.

Do your best to prepare. Put the betta in clean water and starve it for about two days. Pay attention to disease

Step 7.

Be sure to contact the buyer to make sure they will be there when the goods arrive. Use only air cargo or express mail, many fish are dead by the time they are sent by priority mail

If you do not know use which plastic bags for live transportation, Then JTD pack could providing the fish transit bags.