Ok,so lets start...
First,Get 1 of your square pieces of paper (for the same size as my box,make sure it measure 21 x 21cm).

Next... Fold the corners together so it makes an X shape on the square. Here is an example!
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Fold in all the corners like in this picture.
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Next open up the corners and fold the corners to the furthest opposite fold like this.Do this to all corners!
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Cut following the folds but make sure there is still 4 squares left in the middle.Cut on the opposite side.Sorry its hard to explain here's a pic!
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Fold in the other corners twice like so...
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Next fold in the side tips of corners you just folded so it forms a square..
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It should look like this...
<---(repeat step 1-8 for the second square)

Decorate your box now!

Ta Dah!!!

Next add your treats or whatever you want to put in it!

Enjoy your box!