I got this idea from
here, but decided to use cards instead of other pictures. I had to curve the belt a bit to make it fit on my hips and I used self-adhesive film. The buckle is taken from an old and broken belt of mine.
There are some folds on it and the seams aren't perfect, but I still like it.



Edit: Here's the tutorial I promised - please remember: I used a tutorial myself and only changed a few things, credit for the original tutorial goes to Schuldig.groben.Unf
ugs.
I don't know if it's actually understandable, but I tried my best
What you need:
- A deck of cards (you won't need all the cards, though)
- foil (I used sticky foil, you could also use the normal kind like in the original tutorial)
Edit: The stuff is called "contact paper"

It just has a completely different name here...
- a belt buckle
- some eyelets
- small pieces of synthetic leather
- adhesive tape
I started with fixing the cards into a slightly curved belt. It works best to take two cards and let them overlap a tiny bit on the upper side and fix them with adhesive tape on the backside.

Continue doing this until your belt is a bit longer than your hip size.
If your buckle is smaller than the cards you need to cut the belt a bit where the buckle will be. (Black line: original form, red line: new form)

I attached another piece of card for the buckle.

Then I took the other end of the belt and adjusted the width of the cards there, too. It has to fit through the buckle on the overlapping part of the belt, you can see this quite well on this picture:

After that I took the adhesive foil and glued it on the front side of the belt. I cut the foil a bit larger than the actual belt and folded the overlapping parts to the backside.
Then I added two holes for the buckle (depends on the kind of buckle you use) and attached the buckle to the belt.
You can use more adhesive tape for this or add a seam to fix it.
After that I sew around the whole belt with white thread (by sewing machine).
Then I added the eyelets - I tired the belt on, marked where the eyelets should be and marked two other positions, too (one larger and one smaller one)
I glued some small parts of synthetic leather on the backside of the belt (where the eyelets should be), punched holes and added the eyelets.