The slow but resilient Crystalisks are difficult to take down with guns early in the game, even when firing at the three weak points on their legs until they break. Fortunately, there is a much faster (and easier) way to defeat these beasts; simply use melee attacks on the weak points on each of the three legs, but only if you equip a weapons that grant bonuses to melee attacks; even a +50 percent bonus is significant.

"Law" family pistols (which are easily obtained from a side mission in Sanctuary partway through the game) are perfect examples of firearms which grant melee bonuses.

Find Sir Hammerlock inside Sanctuary after completing "A Dam Fine Rescue" mission to get "Mighty Morphi"quest:

1) Injecting a serum into Varkid Cocoons, then kill its offspring (Badass Varkid) to get around 1500-2000XP
2) Kill as many as you want by not completing the quest

In Tundra Express, complete all Tiny Tina's side quests to get "You are Cordially Invited: RVSP" quest.

1) Kill Flesh Stick to get from 1,500-5000XP per kill
2) restart the quest with Tiny Tina
3) Co-op mode: let a player stand by Tiny Tina and the other wait for Flesh Stick's respawn

If you're not adverse to saving and reloading over and over again to make enemies respawn in the game, one way to continually farm Eridium is to repeatedly kill the "Bad Maw" unique mob located just outside the Bloodshot Stronghold, north of the quick travel terminal in Three Horns Valley.

Defeat Bad Maw, head into the Bloodshot Stronghold itself afterward, then save and quit the current game. Simply reload the file, then once back into the game, leave the Bloodshot Stronghold the way you entered and defeat Bad Maw outside again.

Re-enter the Stronghold, save and quit, and repeat ad nauseam!

The following is an alternative way to get weapons:

1) Tip Moxxi in Sanctuary (over $10,000 in total), she will hand you a 1st weapon.
2) After awhile, come back to find Moxxi and tipping her again, she will give you another one!

note: There are only two type of weapons available from her — Fire Elemental Submachine Gun + Corrosive Elemental Submachine Gun

Follow the following instructions to increase your assets:

1) In a Co-op game, trade your valuable with a player
2) Quit the game w/o saving such as sign out or restart the system
3) Log back on to check your assets: if you are done it right, you should still have items that you traded with your friend earlier, and another set of your items should still under your friend's possession.

note: avoid perform "trading" near the auto-save point

In the Vault of the Warrior, hidden chest can be found right by the lava:

1) walk until you see a Metal Bridge inside the cave, stop by the lava stream about 10 feet before the bridge
2) Look down, there should be step-stone liked rocks by the edge
3) Jump onto the lava towards the left wall, now you should able to see the hidden den.

updated: check out the latest Borderlands 2 Neoseeker Video Walkthrough section or here for this cheat

Follow the following instructions to get Head / Skin / Money (available after Ch 9):

1) Go to Sanctuary Hole ( just the northeast of the map in Three Horns Divide), then jump off a cliff behind a building ( there is a place for you to jump onto), now you are at the entrance of Caustic Caverns.
2) Go to the Gurdian Ruins on northwest of the map, go to the minecarts and follow the train tracks to almost the end, then turn right, take the small path, jump over two blocks of rocks and turn left to enter a cave filled w/ blocks at the end.
4) Now you are literally "hit the wall", smash through the blocks , it takes about three hits for one block and there are two walls of blocks, then a secret area reveal.
5) The room is filled with Luxury Surprise + Enemies: such as Diamond + Gold, and Creepers. Kill the enemies to get minecraft skins + head piece for your character.

updated: for a video walkthrough, check out the lastest Borderlands 2 Neoseeker Video Walkthrough section or here