Create a new partition.
fdisk /dev/sdb
Create a new GPT partition table.
g
Create a new partition.
n
Format the new partition with Luks.
cryptsetup luksFormat /dev/sdb1
Add the new encrypted partition to crypttab
with the partition's UUID.
vim /etc/crypttab
Format: [name of the new device] UUID=[xxxxxxxxxxxxxxxxxxxxxx] none luks,discard
storage1_crypt UUID=af847e7b-dcb4-4958-b82a-c6bf59949951 none luks,discard
Activate the new encrypted device.
cryptdisks_start storage1_crypt
Create filesystem on new crypt volume.
mkfs.ext4 /dev/mapper/storage1_crypt
Add device to fstab
vim /etc/fstab
Format: [device] [mount point] ext4 defaults 0 0
/dev/mapper/storage1_crypt /mnt/storage1 ext4 defaults 0 0
Create a FS on the new luks partition
mkfs.ext4 /dev/mapper/storage1_crypt
Mount the volume.
mount -a