A Little Tab'll Clue Ya
Lastly, if you're having trouble seeing things--whether it be loot on the ground or enemies on the horizon--hit the Tab key. It will highlight anything you can use, talk to, pick up, or attack.
Feats and Skills
While the game has a wide variety of feats and skills to choose from, there are a few that are simply mandatory for certain classes.
Every character should put some points into disable trap. While you may not need it for chests, you will definitely want it for door and floor traps. If you have a decent intelligence, you'll generally have some extra skill points with each level. Throw them here and you won't be sorry.
Fighters have one skill that is absolutely mandatory: cleave. It lets you take a free attack on a nearby opponent if you deal a killing blow. Cleave will make groups of low-level monsters fall to the ground like dominoes.
Other good fighter feats include knockdown, improved, and critical. Power attack is good for fighting low-level creatures (as is the improved version. Characters with higher dexterity than strength (such as monks) should also take weapon finesse.
Rogues and rangers (and any character that prefers ranged weapons) should take point blank shot and rapid shot. For rogues, these feats combined with the class's sneak attack bonuses make for a very powerful ranged weapon fighter.
The spellcasters' metamagic feats aren't so cut and dried. The loss of a higher-level spell slot to make a low-level spell more powerful or faster may not be worth it to you. Spell focus, however, is a great choice, and you can choose it several times to apply to different schools.
Rogue Skills
It may seem daunting at the beginning: Your spellcaster doesn't have any thieving skills, and so you can't open the high-class chests to get the good loot. But you don't want to take Tomi as a henchman, because you need a decent tank.
There are plenty of ways to open a chest, and at higher levels a spellcaster is just as good as a rogue at opening and disarming chests. How? Direct damage spells. Not only will direct damage spells destroy chests easily, but they will also instantly disable any locks. Alternately, melee classes can bash them open, and no chest is a match for high strength and a good weapon.