zfs create            zroot/jails/templates/template01
bsdinstall jail       /usr/local/jails/templates/template01

mkdir                 /usr/local/jails/templates/template01/basejail
mount -t nullfs -o ro /usr/local/jails/basejails/bsdinstall_jail \

# delete and recreate /usr
rm -rf  /usr/local/jails/templates/template01/usr
mkdir   /usr/local/jails/templates/template01/usr

# link stuff from basejail into usr
ln -s ../basejail/usr/* .

# create exceptions, local to the jail for which the template is
rm     local obj tests
mkdir  local obj tests

cd /usr/local/jails/templates/template01

chflags -R noschg  sbin           rescue           libexec           lib           boot                        bin
rm -rf             sbin           rescue           libexec           lib           boot                        bin
ln -sf             basejail/sbin  basejail/rescue  basejail/libexec  basejail/lib  basejail/boot basejail/bin  .

force a shutdown

jail -r