Im just starting to play this, I finished FFX yesterday and Im starting this now... I played it when it first came out a few years back, but for some reason it didn't click with me, (neither did FF9 but I finished that last summer and I really enjoyed it) but Im giving it another chance now...  Its weird, I have pretty much no memory of this game, I vaugely remember the first city of the game, and some sort of big thing drilling like platform in the desert but aside from that nothing...
 
So aside from the obvious grind like crazy any tips? One of my friends told me of some chests not to open to get a spear, anything else? Keep this relatively spoiler free please :)

figure out which characters you want to turn into tanks and healers.   Then go from there.

There is a super-spear later in the game which is more powerful than any other weapon. It is found in a chest that will always contain it. However, if you open one of five random boxes in the world, that 100% chance drop becomes a 1/1000 chance drop. Find the list of boxes, and memorize it!
 
Other than that, be aware that the game is an open-world JRPG (think WoW, not GTA), so you can run into very powerful shit very early. This can be good (fast leveling!) and dangerous (one hit kills!). So be careful when travelling.

However, if you open one of five random boxes in the world, that 100% chance drop becomes a 1/1000 chance drop.

I finished replaying FF10 yesterday and I wanted to replay 10-2 after but my room mate was really really against it, I dunno why.... I actually enjoyed it..

@Beforet said: 

However, if you open one of five random boxes in the world, that 100% chance drop becomes a 1/1000 chance drop.

What. The. Fuck? Really? I've never played FFXII, and haven't played many Squeenix games, but Really? How is that okay? To anyone...for anything...ever?
 

Why would you need hints for playing this game? It plays itself.

I grinded for a good five or so hours before I even went into the story, and that's really all you have to do.