Bard charm doesn't last long, in a duo with a necro you should probably used any chants and manasong.
Soloing is another story. :) Depending on your level you can fear kite, mezz tank, chant kite or swarm kite.
Fear kite= chain snare, fear, haste if you want or a resist debuff then melee on it's back while it runs.
Mezz tank = Slow, melee songs, when you get low HP, mezz the mobs and regen up, repeat.
Chant Kite = Best dots on 1 mob at a time.
Swarm Kite = pull a bunch of social mobs, charm one, have it attack it's buddies, break charm (invis) just before pet dies, chant it down for full xp.
Swarm kiting is the best solo xp you can get once you figure it out and get the hang of it. Fear and mezz keep your off/def skills up, chant kiting is the safest XP you can get solo.