Following my first Tetra Pak wallet Instructable made from milk cartons , I have tried different folding methods, alternative currencies and different Tetra Pak cartons. The most common carton especially in the US and Canada is the 2 Litre juice carton. After making a few of these, I believe that these work particularly well for a wallet.
Since this is very easy to make I will attempt to describe this in as few steps as possible.
Step 1: Cutting the form
Cut the 2L carton open down the seam at the side. Cut the bottom portion off.
Cut half of the top sections. If the carton has a plastic screw top, simply rip it off.
Cut each side, next to the main panels, in half.
The product should look like the second image
Step 2: Folding the seams
If your wallet is currency specific, e.g. you country has dissimilar sized noted and some are very tall, then get the largest note to size up your wallet. Fold along this seam.
Next get cards that belong in your wallet to size up the card sections. Fold along this seam also. Follow the picture for the next three cuts. The first cut will be a "V" in the top flap - this will aid in the wallet actually folding together. The other two will be on the side so that the wallet can hold together without glue.
Step 3: Folding together
Fold the last 2 flaps that you cut into the card flap. Repeat for both sides. With 2 more cuts your wallet should be finished! Once folded up, cut a diagonal on each of the card flaps to allow you to get at the cards. The flap at the top of the wallet with the "V" cut should be folded down. This gives your wallet a little strength on the outer edge.
You may find it useful to crease and score the edges to make the wallet sit flat. I use the handle of scissors to flatten them out - and it seems to work well.
Now fill your wallet with cash and go and spend some money!