At your level, you should have a specific talent in the Feral tree:
Feral Instinct 3 / 3 points invested.
Basically that increases your stealth level in cat form (only useful in tanking when you want to scout out an area to best arrange pulls) and increases your threat by 15%. Dire bear increases your threat by 1.3 x base value, or 30%. This basically gives you 45% more threat than a normal, non-modified attack.
Now, on to the abilities. At level 38, you should have Maul, Swipe, Challenging Roar, Growl, Feral Charge, Demoralizing Roar, Enrage, and Feral Faerie Fire.
Right before you pull, pop Enrage. Then hit the focus mob with Feral Faerie Fire. This should give you enough rage to lay down a Swipe as soon as the mobs get in your face. Next, Demoralizing Roar. This gets you some AOE threat and debuffs the mobs so you don't take too much damage. Then keep mauling / swiping the mobs. If a mob splits off you, feral charge it, growl -> maul, and switch back to the focus target.
Make sure dps knows to attack the focus target. Make sure hunters have growl on their pets off. And realize that retribution paladins WILL pull aggro from time to time. It is because their damage is very spiky and they have no threat wipes. Same with Enhancement shamans and warriors.
Once you get higher in level, you will get Mangle and Lacerate. These moves will tremendously help with threat generation.
You can also cast Regrowth and Rejuvenation before the pull. Every tick of these heal-over-time spells will generate AOE healing aggro. Or for a one or two pull, you can do something fun like mark the first kill with skull, second with x. Blast the x with a Starfire and then hit the skull with a Moonfire, then switch to bear form. If it's a grouped up pull of like 5 mobs, I will often pull them with Hurricane, switch to Bear form and pop enrage.
Just experiment. You are a druid, you have a ton of tools at your command. Use them. If it's an Outdoor instance like Zul'Farrak or Old Hillsbrad Foothills, don't be afraid to root melees or something like that.
For example, one fun thing I like to do in instances like Sethekk Halls or Slave Pens is to Hibernate mobs. You see, you'll get a 5 pull of mobs. 2 undeads, 2 humanoids, and 1 beast. I'll mark a sap / sheep / trap, mark the beast for hibernate, and then pull them by hibernating the beast.