honestly how slim a wallet can be depends on the **** you put in, the thinnest wallet would be:
1. drivers license
2. debit card
3. thick rubber band
pretty much as essential as you can get, most of us drive and quite honestly you just need to carry ID w/ you, debit card doubles as cash and credit and a thick rubberband is just an old school way to keep **** together.
Front or back pocket?
I've seen this "revolution" where ppl are putting wallets in their front pocket, why? is your wallet so fat full of rewards cards you need it like that? (cuz fat wallets in back pockets give ppl back problems)
Again lets break it down,
essential
1. drivers license
2. debit card
needed to live
3. insurance card
work
4. work credit card (usually this is the amex)
5. work id (usually you have this separate, either lanyard or clip)
should be carried but never is
car insurance/registration should really be in wallet, not in the dashboard, but who does this.
function cards
i.e. (i have a card i need to use for my unattended parking / also my laundry is a card that's chipped)
How to simplify?
for me since my car needs the card badge to go into/out of the garage, i just leave it in my car
Also since i do my laundry w/ my car, my laundry car is there too (along w/ detergent/softner in the trunk)
Since modern life does not happen with a smartphone any "rewards card" is put on my smartphone with apps like "keyring"
some of us can't have "thin" wallets too, maybe you always need a receipt, for travel/itemization, heck maybe you're a euro guy and you need to use those silly coins, so you have to have a tiny purse around to carry your change. (when we were travelling in italy, i gave wife all the coins, since like most women she has a big ass wallet with a coin purse)