Another thing that hasn't been mentioned is timing the recharm. As soon as
your pet is charmed and sent to attack, you should start up a song. If I'm
injured I use Hymn, otherwise I use Selo's. As soon as it pulses, I stop it
and start a second song. Selo's for sure this time. As soon as it pulses I
stop it and count to 4 or 5 slowly, as in 1 one thousand 2 one thousand...
between the 4 and the 5 I will start the charm song. Usually I will get a
charm wears off followed by a glazed message before the mobs have taken more
than a couple of steps toward me. If I get a resist I will pulse Selo's
again before trying another charm to avoid getting pounded.

Another thing I've started doing is... as soon as the pet is recharmed I
will run past the mobs and turn to face them again. This way I do a better
job of avoiding wanderers, and usually end the fight at approximately the
place it started. I've tried using other views but find them less
immersive.

Once my pet has won, I will wait for the charm to wear off, lead it a little
distance from the corpse, recharm it and issue a /pet guard here command.
Then I can go loot the corpse without getting jumped.

One mistake I often made at first was going to find another mob and charming
it to kill off the first pet. The problem with this is that the first pet
will completely ignore second pet and attack me. If I ran the second pet
wouldn't be in melee range, so I usually ended up zoning. Now I just
chain/fear my original pet.

It's been my experience that it's not a good idea to charm a magic user,
especially one that can heal. It will heal it's opponent somewhere along
the way. I'm not sure if it does it before it can be recharmed or while
it's charmed, I just know it get's the job done.

Hope this helps,

Tomerrilin