I use USPS Media Mail. Flat rate shipping. Shipping time is 3 to 7 days. Price is like 2.50 up to 1 lb. Up to 2 lb is 2.98. Kinda cheap. Might want to try a third party service because you cant use media mail thru usps.com. You have to go to the post office or use an online service line stamps.com to use media mail.
Props to you saijin on keeping it low key. I have used kitchen towels and newspaper if I feel like it...double points if your toilet paper is USED saijin sir /nod