One thing I like to do to make my life easier is to get the Very Large Ember just before I reach Anor Londo (allows you to make a +15 weapon!) In this video I make my way to New Londo Ruins, lower the water and try to make my way to the ember without dying. At around level 45-50 it's not easy for me, but I get it done and waste a lot of humanity in the process (in case I ran out of Estus Flasks). To get the key to lower the water, you can use a bow to kill the NPC from a distance. This will save yourself a LOT of frustration from the ghost's "gank" attacks. I died once on my way through here making a stupid mistake! Luckily I had the shortcut unlocked first.