Step 1)Fold the napkin into triangle shape
Step 2)Fold the napkin again in a triangle shape
Step 3) Now fold the napkin in a triangle shape it will form kite
Step 4)Then from folded parts fold the napkin
Step 5) Now turn the same side and fold the napkin
Step 6) Now fold the napkin again
Step 7) Fold the napkin once more
Step8:Again fold the napkin the same way as step7.
Step9)Fold the napkin again this way.
Step 10) Now turn the side and fold the napkin from right side
Step 11) Fold the the napkin from left side and you have to put left side to right side. Now look at front side your bishop hat is ready.
Now have a look at this video to see the tutorial of napkin folding in this way.