There is a large number of people using the lab, and it doesn't take long for the lab to get very dirty. Our cleanliness rule is as follows:
Leave the lab cleaner than when you found it.
This means thoroughly cleaning up your mess, in addition to something else. It only takes a couple minutes to sweep the entire floor or wipe down all the work surfaces. Plan on stopping your work at least 15 minutes before you need to leave, or longer if you've made a big mess. This will give you enough time to properly put away all the tools or components you have used, and to clean up the lab.