The 39 categories of Forbidden Labor enumerated on page 73 are specific. But there are other actions which are not but are forbidden because doing them may lead inadvertently to one of these 39. For example:
IF A CASK [OF WINE] IS BROKEN,[ON SHABBAT] ONE MAY SAVE THEREOF THE REQUIREMENTS FOR THREE MEALS, AND HE [THE OWNER] CAN SAY TO OTHERS, 'COME AND SAVE FOR YOURSELVES', PROVIDED THAT HE DOES NOT SPONGE IT UP
Now on its face, there is nothing wrong with sponging. But the concern is that one may naturally wind up wringing the sponge out which is forbidden.
Ultimately the ideal is not just to stay within certain parameters – it is to note in everyday actions that Shabbat is not everyday.
A Tanna taught: One must not sponge up wine nor dab up oil, so that he should not act as he does during the week.
Our Rabbis taught: If one's produce is scattered in his courtyard, he may collect a little at a time . . . but not into a basket or a tub, so that he should not act as he does during the week.
What can you do to insure that even the mundane is different on Shabbat?