With memory sticks it is best to use the original plastic container that they came in.
Often when I am shipping one, I will place it in the original plastic container then (if the area I am shipping to is known to be having bad weather, I will wrap the plastic container with a few sheets of paper towels) , then wrap it in bubble wrap. then I will fill any empty space around the bubble wrap with packing peanuts. I will then place it in the correct sized box (USPS gives free boxes of many shapes and sizes)
If you don't have the original casing, then wrap the memory sticks in some printer paper (make sure it has a snug fit)
After that, wrap a paper towel around it, then place it in a plastic bad that is large enough to fit it, then tape the bag shut then after that wrap everything in some bubble wrap, then place it all in a box and fill any empty space with packing peanuts
PS for shipping memory, I recommend the USPS small flat rate boxes (never use a padded envelope to ship memory if it doesn't have the original box, the memory sticks will break)