Step 1:
This folding paper is 20x30 centimeters and made of shiny wrapping paper taped to a white paper.
Fold over these two lines.

Step 8:
Fold over these four lines

Step 6:
Fold / press both edges against each other.
Do the same on the other side.

Step 12:
Fold over these two lines.

Step 11:
Fold in half and press the bottom of the glass flat, see arrow. Use glue or tape, if necessary.

Step 10:
Fold / press the edges further downwards.

Step 9:
Fold over these two lines.

Step 5:
Glue / tape the edges together.

Step 7:
This is how the model should look.

Step 3:
Fold over this line and turn the model.

Step 2:
Prefold over these two lines.

Step 4:
Prefold in half, then prefold the edges to the centerline
The left part of the folding lines don't have to be sharp (this will be the cup).

Finally, pull the upper edge outwards, into a circle... Done!
This is an Origami video tutorial for folding the wine glass: