I have my sheet music organized into stacks. The first stack is created by combining several other stacks of loose pages when I'm trying to clean up the house for guests. Then that stack is eventually dispersed into a sub stack system created by searching through the first stack for a particular tune. Once that is found, it goes into another stack on the music stand until there are too many pages and they start falling off. Then the ones on the bottom go into a separate stack and the ones that fell off sometimes get stored neatly under furniture. Once I have enough separate stacks, or if we are having company over, I will then arrange them into the combined stack and start over again. I know where everything is. 
OK, it's not that bad. I have several bins that are loosely arranged by genre. Then I have another bin that are the ones that I am currently working on. Some are in binders, but others are stapled together in collections. But, I do know where everything is, and I try to only have the music out while I'm learning the tune. The one's that are on my above mentioned 'set' list, I try to commit to memory. Of course, that list isn't super long, so I may have to come up with an alternate plan, but it works for now.

OK, it's not that bad. I have several bins that are loosely arranged by genre. Then I have another bin that are the ones that I am currently working on. Some are in binders, but others are stapled together in collections. But, I do know where everything is, and I try to only have the music out while I'm learning the tune. The one's that are on my above mentioned 'set' list, I try to commit to memory. Of course, that list isn't super long, so I may have to come up with an alternate plan, but it works for now.