Decide which credit card & debit cards you use on a regular basis.
For most people, this will include:
Remove the rest of the payment cards you don’t use every week and store them in a secure location at home.
Remove cards like:
Take advantage of your smartphone and put all your gift cards in an app like the iPhone/Android “Gyft” app.
If there are any extras that won’t go in the app; keep them in your car or a secure place at home.
The ones in the app you will always have with you, and the extra's will be safe enough in a drawer until you plan a time to use them.
Add all your loyalty cards & store membership cards to an iPhone/Android app like "Stocard".
Or go even simpler and just use your phone number at checkout. If you can't remember which phone number you created the account with, either update the account or create a new one.
Even if they don't accept a phone number, most stores will accept a digital version of your card. If you're worried they won't, check the website or bring the physical card as a backup the first time you try it.
Keep punch cards in your car, or better yet just toss them.
Take the rest of your cards and decide which one you can add to your phone app, which ones can live in your car, and which ones you need every day.
Some places like Disneyland require you to have the physical season pass, so cards like this would be good ones to keep with you or in your car.
Insurance cards can live in your car with a copy stored on your smartphone in case you’re driving someone else’s car.
It also might be a good idea to create an "emergencies" card with your medical record/insurance info and allergies and attach it to the back of your ID.
Receipts can easily be photographed and kept in an iPhone/Android app like "Evernote" or "Google Drive".
Evernote and Google Drive sync with your computer so you have easy long-term access to them.
For the receipts where you need a physical copy, either store them in an envelope in your car or keep them in your pant or purse pocket. When you get home, take them out and put them in a designated drawer near your door.
Decide how much cash you use per week and only keep slightly more than that in your wallet.
In modern times it's much easier and safer to track your purchases by using cards rather than carry a lot of cash.
However, it’s always helpful to have some on hand for cash only parking, tips, and street vendors.
Your wallet contents just went from the stack on the left to the stack on the right
All you should have left is:
Congratulate yourself on making your life just a little bit simpler.
As a little reward to yourself, throw away that old bulky wallet and get yourself a brand new slim one!