We have ours in folders named by reverse date then the subject, then they all organise into the correct date order. eg:
2013 03 19 e's birthday
2013 03 31 easter
2013 04 trip to coast
etc etc
I also have a "various" folder and a folder for each of the kids for each year (with sub folders for each month) to put in those few snaps that don't fit into another folder.