well, it are goblins... and they're cheap.
basically this means you need a lot of them, really, a lot of them!
as goblins have fight 2, you'll rarely get any bonus dice for FV, so you'll have to get you're dice from somewhere else. this is where the mobs rule rule comes in handy. make sure you have a lot of supporting formations, just to get a lot of dice.
the downside is that for each direct companies you get bonus dice for FV, so for each formation fighting directly he gets more dice, whereas you have even less supporting dice. try to have as few companies fighting directly as possible, and if you feel you need more dice use a second formations, rather then a second companie.
this is also where a shade allied in from angmar comes in handy, as all enemy formations have FV 2, just like you, so you won't have to worry about FV; you take away their advantage, you keep yours.
besides having a lot of goblins its important to have some hard hitters, preferably monsters. this because goblins don't hit hard and space is limited with so many gobbo formations around, and monsters are relativly manouvreble. trolls and spider queens are good. the balrog/dragon are very expensive, and i wouldn't advise using them in anything under 1500 points. but if you're going for a 500 point monster then consider taking 2 hill giants instead of balrog/dragon. these 2 deal twice the pain and can take the same amount of punishment for the same cost.
i'm hoping this was of some use...
