I apologize for the not to great photos.. I had just woke up and was trying to see with eyes that weren't all working yet.. but I think you'll get the idea.
I use my retired Stampin' UP! Photo Corners Punch You could quite possible use a square punch and use one of the corners as well.. look at your punches and see what you have already.. you might have something that will work if you don't have this particular punch.
I slide the strip of card stock I want to punch inside the punch.. you don't even have to put it in as far as I did.. but I wanted you to see the card stock.. then punch. You would do this if you were wanting a single layer strip.. like I did after I stamped the sentiment for these HAPPY BIRTHDAY CARDS I then punched the strips and adhered them to the card fronts.
If you are wanting two layers... I would usually have the white on top and the black as the back layer, these were scraps I had laying on my desk, so I used them for demonstration purposes. Put both ends of the pieces you want to punch, together. Insert them into the punch and punch... NOTE: you could draw a line on the back of your card stock to represent the middle.. that way when you put it into the punch you could line that line up with that point that you see at the end of the strips. you won't be punching that out.. because you don't push your paper in that far.
Here is what the double punched strip looks like.. I had a blue strip laying on my desk and thought I'd show it too.. it's a much thinner strip, but you can punch it as well.
This is how your two pieces will layer on each other when you are done punching them.
If you want to get points at both ends of the strip.. you would trim down your bottom layer to the amount you wish to have showing as the back layer..
You would then slide both ends down together and put them in the punch again on that end, and punch.
Then your two pieces would layer together with the same amount showing around the edges.
hope that helps.. have a super day ahead.
thanks for looking ~
have a great airborne day!
God Bless All Our Military.. each and every one of them