The easiest and fastest way to farm Blood, so far...
How to Farm Infinite Currency and Equipment
In this guide I want to show you an easy, fast and safe way to farm Red Orbs/Souls/Blood. At the time of writing this works perfectly fine every time.
The easiest way I found, is to exit the game right before you face off against the Boss of the second level:
The game will save your position, inventory etc. and all enemies in the level will be dead (even ones you haven't killed) and all doors will be open (even ones you skipped). All chests will be restocked and randomized and all destroyable objects will be back as well. All spots that have a chance of having an NPC, will be randomized, too, so you get extra chances at playing one of the minigames each time. Watch out for traps, though - those are back, too.
So, after quitting to the main menu screen, load your game, safely backtrack through the whole level, collecting everything, head back to the area before the Boss, quit again, load again. You can do this infinitely and be rich and well equipped in no time.
Since the shopping pillars will also randomly be restocked, you can also improve some of your Bloodthirsties by buying Blood Ambers.