1. Create a LUKS Encrypted Logical Volume

assuming you already have a volume group set up

Create Logical Volume

# lvcreate -L [new logical volume size] [volume group name] -n [new logical volume name]
example
# lvcreate -L 100G myVolGroup -n myLogVol1

Format the new logical volume

# mkfs.ext4 /dev/mapper/[volume group name]-[new logical volume name]
example
# mkfs.ext4 /dev/mapper/myVolGroup-myLogVol1

Fill formatted logical volume with random Data

# dd if=/dev/urandom of=/dev/[volume group name]/[new logical volume name]
example
# dd if=/dev/urandom of=/dev/myVolGroup/myLogVol1

Create encrypted layer for the new logical volume

# cryptsetup luksFormat -c aes-xts-plain64 -s 512 /dev/[volume group name]/[new logical volume name]
example
cryptsetup luksFormat -c aes-xts-plain64 -s 512 /dev/myVolGroup/myLogVol1

Create a combined logical volume + encrypted layer

# cryptsetup open --type luks /dev/[volume group name]/[new logical volume name] [new combined logical volume + encryption layer name]
example
# cryptsetup open --type luks /dev/myVolGroup/myLogVol1 myLogVol1_Encrypted

Format the combined logical volume + encryption layer

# mkfs.ext4 /dev/mapper/[new combined logical volume + encryption layer name]
example
# mkfs.ext4 /dev/mapper/myLogVol1_Encrypted

Mount the newly formatted combined logical volume + encryption layer

# mount /dev/mapper/[new combined logical volume + encryption layer name] /path/to/mount/folder
example
# mount /dev/mapper/myLogVol1_Encrypted /home/auser/myEncryptedVolume

2. Automount the Encrypted Volume on Boot

Create a directory to store your keys and make it read-only to root

# mkdir -p /etc/luks-keys
# chmod 0400 /etc/luks-keys

Create a random keyfile for each volume to be encrypted and mounted at boot

# dd if=/dev/urandom of=/etc/luks-keys/<keyfile name> bs=1 count=256
example
# dd if=/dev/urandom of=/etc/luks-keys/myLogVol1 bs=1 count=256

Add the keyfile to each volume to be encrypted and mounted at boot

# cryptsetup luksAddKey /dev/[volume group name]/[new logical volume name] /etc/luks-keys/[new logical volume name]
example
# cryptsetup luksAddKey /dev/myVolGroup/myLogVol1 /etc/luks-keys/myLogVol1

You’ll be prompted to enter the (existing) password to unlock the drive.

Open /etc/crypttab to create a mapper that can then be referenced in the fstab

# nano /etc/crypttab
add an entry like:
# [name of the mapper]    /dev/[volume group name]/[new logical volume name]    /etc/luks-keys/myLogVol1    luks
example
# myLogVol1_crypt    /dev/myVolGroup/myLogVol1    /etc/luks-keys/myLogVol1    luks

Mount the device in fstab

# nano /etc/fstab
add an entry like:
# /dev/mapper/[name of the mapper]  [mount point]   [filesystem]  defaults        0 2
example
/dev/mapper/myLogVol1_crypt  /home/myLogVol1   ext4  defaults        0 2 Make sure you have the correct mapper name created in the previous step and that the mount point/folder exists.

Reboot or remount

to remount you'll have to reload the cryptab before issuing the mount command, like:
# systemctl daemon-reload
# systemctl restart cryptsetup.target
# mount -a