Strop makers. A question.

[Mr Pseudo]

I have a square of leather and I am thinking about trying to make myself a strop.

My question is, should I cut the strip up the leather or across it or up and down? In other words, should the strop run up the cows butt or across the cows butt?

I'm worried about what would be best for stretching, cupping, and other things as the strop breaks in.

Thanks.