various examples of double knots and single knots at the end of a bag.
דבר דבר (Dabair Davar): More About the תפלות Tefillos on Shabbos With Requests;
Collecting Together Items in the House, e.g., Toys, Cutlery, Utensils, etc.
Putting the Little Plastic or Rubber Cups on the Bottom of Chairs or Tables and Blowing Bubbles on Shabbos;