Bottom brackets have radically changed in the past decade. This article will focus on standard old school bottom brackets like the Shimano sealed UN series, which dominated the market for decades. Modern cranks have brand specific instructions for removal.

Bottom brackets move inversely to pedals. Therefore rotation towards the back of the bike tightens, and rotation towards the front of the bike loosens the bottom  bracket.

All too often I had a really hard time removing bottom brackets ( I knew the proper direction to turn ). They are difficult to remove due to flex everywhere, especially in the workstand. I learned a trick, flipping the bike upside down removes the flex from the workstand, hence it is easier to remove the bottom bracket. Try it out, let me know what you think.