I clear the 1st third of the game. I opt for the Catacombs where divinity damage will suit me well. Perfect timing...as I just scored a auto-damaging "miracle" also boosted by faith. I am two short of its minimum requirements so I warp to Anor Londo to take down two giants for their souls.
I can go to Catacombs with no grinding, but a two-tiered faith offense sounds fun. I then detour, at my leisure. I slow, my roll.
Prior, I spontaneously combine with properties that enhance loot drops. I didn't make it to the Catacombs then either. I stack up...with a loot-boosting ring, and hunt for humanities in Duke's Archives and the Depths slaying a dragon in between.
Revisiting content is a pleasure (once you master the controller and download the patch fix.) Dark Souls' difficult reputation regrettably overshadows the fun combat. The real star of Hidetaka Miyazagi's Dark Souls, however, is the level design.
Take Anor Londo. I can pop a humanity and summon help against these two bosses. However, there is a chance rather than summoning help, a player enemy raids. If the raider appears too late, he might find he is up against you, your friend, and your NPC. You might still lose, but will learn, and will rise again.
....or you can skip all that summoning and proceed to the final bosses. Built up enough souls that you don't want to risk losing them? Level up. Don't have enough to level up? Hang left and spend it on supplies. See something at the black smith that you can't afford? Stop short of the bosses and take down their guards for currency.
Had enough of Anor Londo but haven't unlocked fast-travel? Easily proceed passed the vendor among the harrowing ground you did unlock.
Lordran -- the land of Dark Souls -- is a meticulous masterpiece of inter-playing maps and interlocking secrets and challenges. You, your mighty build, and a hefty dose of 'googling' forges you into Lordran's master-survivalist.