Get a ripe pomegranate.
Fill a large bowl 2/3 full with cold water.
Pick out the pulp that has floated to the top of the water.
Dry the aril on some paper towels. Make sure to remove as much moisture as possible. This is especially important if you plan to store them in the fridge for later and don't want them to get moldy.
Now you can eat the aril, use them for a recipe or put them into the fridge in dry paper towels and some tupperware. They will last up to a week in the fridge but the first few days are the tastiest!