Measuring for a mitzvah - "מדידה של מצוה". Preferably should be done on "ערב שבת".
Understanding the Concept of Using the Side of a Tree or Using Something Hanging or Sticking Out of a Tree. Is One Allowed to...
How to cut into cakes with lettering on top. (E.g. Happy Birthday cake).
more examples of "מבטל כלי מהיכנו" (nullifying a vessel from its normal usage) that come up on Shabbos;