For my reference, but anyone else too… Creating a new Wireguard public/private key pair and bringing up a new client:
wg genkey | tee /etc/wireguard/private.key
cat /etc/wireguard/private.key | wg pubkey | tee /etc/wireguard/public.key
# Optional
vim /etc/wireguard/wg0.conf
wg-quick up wg0