There is 2 ways that you can do this either

If you happening to be AOEing on Old School RS Gold mobs, Well your job just got a little bit more RS Gold difficult. There's 2 ways that you can do this either in Humanoid or Tiger form.

While in humanoid you'll want to just use Splitting Earth every 8-10 seconds or so after you've got some mobs following you.

Even though while in Humanoid you only have to use 1 skill, the downside is that you won’t have as much speed as in tiger as well as your hiero taking a slightly heavier beating.

If you decide you want to lure while in tiger what you are going to want to do is aggro the mobs and cast tigers presence.

Depending on how far you need to lure the mobs you may need to use either Tigers Challenge or Sundering Heavens to keep the mobs going. I however highly suggest using Humanoid to lure until you've figured out how to micro manage your barbarian very well. Summary:

-Always keep an eye on the Priest, Mage, and Archers health.

-2 mob types, Passive and Aggro as well as luring strategies for each.

-2 luring styles, Humanoid and Tiger.