some people are fortunate in that they don't have to carry too many things in their wallet. i do well most of the time with my tom bihn clear organizer wallet. the ultrasuede dividers help me to keep the contents organized, and the design of the wallet doesn't add to the bulk of what i am carrying.
i have my driver's license, work id and metro rail card, in the first section.
the middle section holds my credit cards and atm cards.
and the last section holds cash and receipts that i want to hold onto short term.
i can easily carry the wallet in any bag or slip it into my pocket when i'm not carrying any bag.
but there is the other stuff that you don't need all the time, but that you still want to keep easily accessible and organized on the occasions that you do need them.
for me, these are the health insurance card, car insurance card, various discount/membership cards, store credits, and gift cards.
i keep these in a second clear organizer wallet that i keep in the bag that i am carrying. i can also leave them behind when i just need to take my wallet in my pocket.
this keeps those cards easily accessible, but keeps them out of the way when i don't need them.