I just figured something out in Azurick that is going to help me tons for the rest of the game,.. and I hope it can help you too,...

if you watch the power fuel globes that the creatures drop after taking them out,..

Look at the colors they drop, before you pick them up,.. some times they drop one or two or even three,...

but really watch the colors that they drop most,.. like the pesky Harvesters,.. drop mostly green and blue power fuel orbs,... that makes acid,.. acid kills them quick!,.. man this is really going to help

And the Rock Shard Creatures drop Green, Red, and Yellow,.
that combines to make the Smash Power Axion,... and this Axion Combo takes them out quick!

I'll try to post more as I figure them out,..
you can add to the list if you figure them out too,..

-Tazilla