Playing together is the best ways to experience Monster Hunter 3 Ultimate. Taking a powerful creature down by yourself is one thing, teaming up with three buddies and dropping one is even more satisfying.
That said playing together in Monster Hunter comes with its own collection of issues and considerations that can be infuriating for some, but if you stick to the following ideas then you should at least avoid making a fool of yourself in front of others, never mind what they are up to.
In it Together
When playing together you all work to the same score sheet. That means you win together, but you also fail together. The 'three faints and out' rule still applies, and it applies to you all as a group. Three faints between you, and it's over.
Playing cautious becomes more important than ever, as you don't want to be the one to lose any of those marks, let alone all three. Play careful, your ability affects the group.
Find a Space
It's easy to accidentally hit a friend with your weapon and while small nicks mean nothing, large attacks can send allies flying. It doesn't hurt much, but it is annoying and can put others in harms way.
As such, pick where you attack a Monster carefully – you want to focus on a part of the monster where your friend isn't. If that means hitting a Monster's head once then moving away from an attack, so be it – it's better than all of you trying to squish in under its legs.
It's hard to play bow in single player, but it comes into its own in multiplayer. Not only are you not getting in your friends' way, but the monster will have other hunters to focus on and leave you to your aim. Not many people choose to play the ranged hunter, you can be unique by filling that slot.
Monster Hunter isn't strictly about team build, that's the realm of the MMORPG, but it's got squad aiding elements for those willing to explore them.
The most obvious of these is the Hunting Horn, a weapon that can apply buffs through the use of a colored note system. If your allies use Dual blades or Hammers, in particular, then a Horn with Stamina buffs can be a huge boon to a team.
Be Prepared (still)
There may be more of you but that's no reason to neglect preparations. Eat a meal, grab your Mega Potions and Nutrients and yes, bring some bombs and traps. There are four of you, that means four lots of flash bombs, traps and what not if you're all prepared!
Remember, smart use of the Farm can ensure you have a huge back-up of valuable combat items.