The braided technique is going to start to work best when you have a triangle shape but you can start with an oddly shaped crumb and build it up to a triangle shape if you like.
It doesn’t matter which side you add your second scrap to first. Just find a straight edge on your first scrap and add a second, right sides together.
Now take another scrap and sew it to the opposite side of your triangle (ish) shape.
Just trim that short edge to a straight edge and add another scrap. You can even use several and create a secondary braid pattern to your block.